Phyphox file format

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This page discusses technical details. There is a simpler and probably more convenient approach by using the visual experiment editor.


This page is highly technical and meant for advanced users who want to control every minute detail of their experiment. On this page you will learn, how the phyphox file format works and how to create a phyphox experiment - all you need is a text editor. Some experience about the XML format is recommended.

Structure

The phyphox format is based on xml. The entire experiment is encapsulated within a phyphox root tag. Within this block, there are multiple blocks which allow to define data-containers, inputs, outputs, translations, analysis etc.

<phyphox version="1.0">
    <title>Experiment title</title>
    <category>Experiment category</category>
    <icon>
        ... Defines which icon should be shown ...
    </icon>
    <description>
        ... A description of the experiment ...
    </description>
    <translations>
        ... Translations into other languages than English ...
    </translations>
    <data-containers>
        ... Defines data buffers to hold sensor and result data ...
    </data-containers>
    <input>
        ... Inputs like sensors or the microphone ...
    </input>
    <output>
        ... Outputs like the speaker ...
    </output>
    <views>
        ... Different views, defining how the results are presented to the user ...
    </views>
    <analysis>
        ... All the math goes in here ...
    </analysis>
    <export>
        ... Export sets define how data-containers are grouped and named when exporting them to a file ...
    </export>
</phyphox>

Block: phyphox

The entire experiment is defined within the phyphox block. It has a single attribute, which is the version of the file format (not the version of the app). If the file format changes in future version, this version number will increase. If phyphox (the app) encounters a file version newer than what it can read, it will not load the file but ask the user to update the app.

Tag: Title

<title>TITLE</title>

The title of the experiment. This is just a simple string. Try to keep it short and concise.

Tag: State-Title

Available since phyphox file format 1.5 (phyphox 1.0.7)

<state-title>TITLE</state-title>

This should not be used for a experiment, which will be distributed. This tag contains the title given by the user when saving the state of an experiment. If this is set, the app will show this experiment in the saved-states section.

Tag: category

<category>CATEGORY</category>

The category of the experiment. This is just a simple string used by the app to group the experiments. Try to keep it short and concise.

Note that this can and should be translated if you use translations (see below) as the app uses the localized version of this string and cannot match your experiment to the default group if the category is given in a different language.

Tag: icon

<icon format="FORMAT">ICON</icon>

The icon of the experiment. The attribute format controls whether ICON is just a string or a base64 encoded image. If it is a string, phyphox will take the first three characters (using fewer characters is ok) and create a simple icon with these. If it is a base64-encoded image, phyphox will decode it and display the image.

We recommend to use a small PNG with few colors as an icon. There are various web-based tools to create a base64-encoded PNG from a PNG file.

format
Can be string or base64 and controls whether the icon should be interpreted as a string or as a base64 encoded image.
optional, default: string

Tag: color

<color>COLOR</color>

The base color for the experiment. This is used as a background of the icon (if a text-based icon is used or if it has a transparent background) and for the label of the category. If a category contains experiments with different colors, the most common color is used.

Color can be defined as a 6-digit hex value or as one of the named Colors.

Tag: description

<description>DESCRIPTION</description>

A description of the experiment. The first line should be a very short information of what the experiment does as this line will be shown in the experiment list. Any white spaces at the beginning and end of DESCRIPTION as well as in each line will be stripped.

Tag: link

<link label="LABEL" highlight="false">URL</link>

A link-Tag defines a link to some resource on the web. You may have multiple link tags in your phyphox file and they will be listed as a button each under the experiment description. When the user pushes the button, he will be redirected to the URL (usually in a web browser, but it might be a specific app for a specific URL - for example Youtube links usually open in the Youtube-App in Android). If the attribute highlight is set to true, the link will also be featured in the experiment menu. (Note, that the highlight attribute is meant to highlight especially relevant links, like instructions for the experiment. Its actual implementation, i.e. the way a link is "highlighted" might change in newer versions.)

Block: translations

The translations block may hold one or more translation (note: singular) blocks, describing the translations of strings shown to the user. Any string outside the translations block is considered to be in English and then translated to other languages from within the translations block, unless a different global language has been defined in the tag of the phyphox-block or if English appears explicitly as a translation block. If English is used in a translation block and no language has been defined in the phyphox-block, the text outside the translation block should be treated as a placeholder.

<phyphox version="1.0">
    <title>My experiment</title>
    <category>Example</category>
    ...
    <translations>
        <translation locale="de">
            <title>Mein Experiment</title>
            <category>Beispiel</category>
            <string original="Some string used in the experiment.">Ein im Experiment genutzter String.</string>
            ...
        </translation>
        <translation locale="fr">
            <title>Mon expérience</title>
            <category>Exemple</category>
            <string original="Some string used in the experiment.">Une chaîne de caractères utilisèe dans l'experiénce.</string>
            ...
        </translation>
    </translations>
    ...
</phyphox>

Block: translation

Each translation block holds all the translations for a single language. The attribute

locale
Defines the two-character iso language code for the translations within this language block. (for example "de" for German or "fr" for French)
required


Tag: title

<title>TITLE</title>

Localized version of the title tag in the phyphox-block (see above). If the user's locale matches the locale of the translation block, the title will be replaced by this entry.


Tag: category

<category>CATEGORY</category>

Localized version of the category tag in the phyphox-block (see above). If the user's locale matches the locale of the translation block, the title will be replaced by this entry. Note that phyphox will group experiments by the localized version of the category.

Tag: description

<description>DESCRIPTION</description>

Localized version of the description tag in the phyphox-block (see above). If the user's locale matches the locale of the translation block, the title will be replaced by this entry.


Tag: link

<link label="LABEL">URL</link>

This is the localized version of the link-Tag. For example, if you link to a Demo video in English with <link label="Demo">http://site.org/my/english/video</link> you can link to a German version in the translation block with <link label="Demo">http://site.org/my/german/video</link>

Tag: string

<string original="ORIGINAL">TRANSLATION</string>

Use the string-tag to translate any string shown to the user besides the title, description or category. If the text of a label, view etc. matches the string in ORIGINAL, phyphox will display TRANSLATION instead. (Of course, this only applies if the user's locale matches the translation locale.)

original
The string which should be translated with TRANSLATION. This has to be an exact match.
required

Block: data-containers

In data-containers all buffers are defined. Any input (sensors, microphone) write to these buffers, any analysis module performs its operations on these buffers, the output modules read from these buffers and the results are shown to the user from these buffers. The buffers connect every module of the experiment.

<phyphox version="1.0">
    ...
    <data-containers>
        <container>Buffer 1</container>
        <container size="1000">Buffer 2</container>
        <container type="buffer">Buffer 3</container>
    </data-containers>
    ...
</phyphox>

Tag: container

<container size="INTEGER" init="FLOAT" static="BOOLEAN">NAME</container>

The container tag defines the name of a single data container. For now, the only container type is buffer, so the attribute type can be left out - It is only there for future new container types.

The buffer type is a queue of a fixed length. New data is appended until the buffer is full. If data is appended to a full buffer, old data is removed from the other end. Any module reading from the buffer will receive the whole data set. However, if the module only requires a single value, it may access the last added value directly.

The size can be set by the size attribute, which defaults to 1.

Infinite buffers are allowed and can be achieved by setting size to zero. However, you should be careful when using this. Never keep filling an infinite buffer if it is the base for complex analysis as this will lead to extreme load when the experiment runs for a long period. Also, infinite buffers are not allowed to hold the recording from an audio input.

type
The only type supported right now is buffer. This attribute can be ignored for now, but other container types may be added in the future.
optional, default: buffer
size
The size of the data-container. For the buffer type this is the number of values, the buffer can hold.
optional, default: 1
static
If set to true, the content of this buffer should only be written once. Analysis modules writing to this buffer will not execute if all output buffers are static to improve performance. This should be set if the content does not depend on measured data.
optional, default: false
init, Available since phyphox file format 1.3 (phyphox 1.0.4)
If set, the buffer will be initialized with the given value when loading the experiment as well as when clearing the data. If not set, the buffer will start empty. Since file format 1.5 (phyphox 1.0.7) you can also separate multiple values by comma to initialize a buffer with multiple values.

Block: input

The input block defines all hardware inputs such as sensors or the microphone used in the experiment.

<phyphox version="1.0">
    ...
    <input>
        <sensor type="pressure">
            <output component="x">Pressure</output>
        </sensor>
        <sensor type="accelerometer" average="true" rate="0.5">
            <output component="x">AccX</output>
            <output component="y">AccY</output>
            <output component="z">AccZ</output>
            <output component="t">AccT</output>
        </sensor>
        <audio rate="48000">
            <output>recording</output>
        </audio>
    </input>
    ...
</phyphox>

Input module: audio

<audio rate="INTEGER">
    <output>BUFFER</output>
    <output component="rate">BUFFER</output>
</audio>

The audio tag defines audio as a data source (i.e. a microphone). Phyphox will record continously and write the recording to the buffer at the beginning of an analysis execution (see analysis block). The target buffer is defined with a simple output-tag.

The default recording rate is 48kHz, but can be changed using the rate attribute (in Hz). However, this is not recommended if the experiment targets a wide audience since supported recording rates are very device specific. Also, the rate you set is not guaranteed. Instead you should read the actual rate from the rate output (see example above) and use that for any calculations that use a time base. Note that the rate output is written independently from the recording output (mostly when the rate changes, which usually only should happen if the audio setup changes). Therefore you should not delete this buffer while reading it. The rate output is available since phyphox file format 1.6 (phyphox 1.0.10)

rate
The recording rate in Hz.
optional, default: 48000


Input module: bluetooth

Available since phyphox file format 1.7 (phyphox 1.1.0)

The bluetooth block defines an input from a Bluetooth Low Energy device. Please refer to the documentation on the Bluetooth Low Energy interface in phyphox for details.


Input module: location

Available since phyphox file format 1.5 (phyphox 1.0.7)

<location>
    <output component="x">BUFFER</output>
    ...
    <output component="t">BUFFER</output>
</location>

The location block defines an input from the GPS sensor. The data will be written to the output buffers at the rate as it is provided from the sensor. On Android, the location data is expected to come from satellite navigation exclusively (although some unusual implementations may occur), but on iOS we cannot deactivate other sources. Therefore in most cases on iOS the first reading is based on the mobile and WIFI networks.

There are several components for the outputs:

lat
Latitude in degree
lon
Longitude in degree
z
Height (note that height provided by GPS is generally rather imprecise) in meters
v
Speed (provided by the system, based on consecutive GPS fixes) in m/s
dir
Direction (determined by the system along with the speed) in degree (counted from north towards east)
accuracy
An estimate by the system of the horizontal accuracy in meters
zAccuracy
An estimate by the system of the vertical accuracy in meters (not on Android)
satellites
Number of satellites used for this measurement (not on iOS)
status
-1 means that GPS is unavailable (usually deactivated by the user), 0 means that it is searching for a signal, 1 means that it is active. 2 means active, but the altitude is given above the WGS84 ellipsoid instead of the geoid, which can happen in the case of very basic GPS implementations on some (mostly cheap) phones. Note that this value is updated independently from the other outputs.

The location tag has no additional attributes.


Input module: sensor

<sensor type="TYPE" average="BOOLEAN" rate="FLOAT">
    <output component="x">BUFFER</output>
    ...
    <output component="t">BUFFER</output>
</sensor>

The sensor block defines a sensor as an input. The data will be written to the output buffers at the rate as it is provided from the sensor. Alternatively, you may define a different rate, in which case the latest reading is picked at the given rate. In addition you may turn on averaging in combination with the forced rate, in which case all data during the interval of the rate is averaged and only the average is written to the buffer.

Many sensors (accelerometer, magnetometer, gyroscope) are 3D sensors writing to a total of four buffers (x, y, z and timestamp t), but you do not need to attach a buffer to all outputs. Also some sensors are only 1D (pressure, light) and will only fill the x buffers. The outputs are mapped to data-containers by simple output-tags. Each requires a component attribute set to x, y, z or t to map the data o the data-container.

Since file format version 1.4 (phyphox 1.0.6) there is another output abs which gives the absolute (sqrt(x*x+y*y*z*z)) for 3D sensor data.

Since file format version 1.5 (phyphox 1.0.7) there is another output accuracy which gives information about the current accuracy. Typically, "-1" means that the sensor is uncalibrated (which might be an error state), "0" means that uncalibrated raw data is presented (but this is expected) and positive values represent accuracy in a way specific to the sensor. This is currently only used by the magnetometer, which encodes its accuracy as 1 low, 2 medium and 3 high.

If a sensor is not available on the device, the experiment will notify the user and refuse to work.

Note, that the somewhat cumbersome names for "acceleration with g" and "acceleration (without g)" have been chosen to aid students in understanding the data given by these sensors. But internally we stick to the names commonly used in the Android as "accelerometer" and "linear_acceleration". Usually, "accelerometer" (the one with g) is a physical sensor which measures the acceleration force applied to a sample mass (in form of a MEMS device), so it will give a constant acceleration of 9.81 m/s² for a resting device (hence our descriptive name "with g"). In contrast, "linear_acceleration" is usually just a virtual sensor, which may use additional sensors to remove the earth's acceleration (hence our descriptive annotation "without g") to report the actual acceleration of the phone in the reference system of the user. So "linear_acceleration" will report zero acceleration when the phone is resting and moved at a constant speed.

type
Defines the sensor type to be used. Allowed values:
accelerometer
The accelerometer in m/s². This gives the earth's acceleration when the device is resting. (Usually named "acceleration with g" in phyphox)
linear_acceleration
A virtual sensor giving the actual acceleration of the device. Should report zero when the device is resting. (Usually named "acceleration (without g)" in phyphox)
magnetic_field
Readings from the magnetometer in µT
gyroscope
Readings from the gyroscope in rad/s.
humidity
Relative humidity in %. Available since file format 1.7 (phyphox 1.1.0)
light
The illuminance from the light sensor in lx
pressure
The air pressure from the barometer in hPa
proximity
Distance from the proximity sensor in cm (most devices only output 0cm or 5cm)
temperature
Temperature. This is supposed to be ambient temperature, but we have some fallback logic to find any temperature reading from the device. This usually represents the device temperature and cannot be used for external temperature measurement. (in °C) Available since file format 1.7 (phyphox 1.1.0)
required
rate
The rate at which sensor data will be provided in Hz. A value of 0.0 means "as fast as possible". Note that the maximum rate of a sensor is device-specific and will limit the rate set with this attribute.
optional, default: 0.0
average
If set to true, instead of just giving the latest reading at the defined rate, the sensor data will be averaged over a period of the rate. This only makes sense if a rate is set, which is lower than the maximum rate the device can achieve.
optional, default: false

Block: output

The input block defines all hardware outputs such as the speaker used in the experiment.

<phyphox version="1.0">
    ...
    <output>
        <audio rate="48000" loop="true">
            <input>waveform</input>
        </audio>
    </output>
    ...
</phyphox>

Output module: audio

<audio rate="INTEGER" loop="BOOLEAN">
    <input>BUFFER</input>
</audio>

The audio tag defines audio as an output (i.e. a speaker). At the end of an analysis period phyphox will write the input buffer to an internal audio buffer and start the playback, so the sound is played after each analysis execution. The input target is defined with a simple input-tag. If the input buffer is static, phyphox will only write it once to the audio buffer, but still play it after each analysis execution.

If the loop attribute is set to true, the playback is looped. If the input buffer is not entirely filled, it will be written periodically until the audio buffer is full. This repeated data should not be played as the looping is done by defining a loop over the length of the buffer data. However, if the loop interval becomes too short, some devices refuse to loop over such short ranges and in this case, the loop will happen because of the repeated data. This will lead to irregular loops if the buffer length is not a multiple of the written data.

The default playback rate is 48kHz, but can be changed using the rate attribute (in Hz). However, this is not recommended if the experiment targets a wide audience since supported playback rates are very device specific.

rate
The recording rate in Hz.
optional, default: 48000
loop
Loop playback
optional, default: false


Output module: bluetooth

Available since phyphox file format 1.7 (phyphox 1.1.0)

The bluetooth block defines an output to a Bluetooth Low Energy device. Please refer to the documentation on the Bluetooth Low Energy interface in phyphox for details.

Block: analysis

The analysis block describes all the math required for the experiment. Each element within this block is executed consecutively and usually reads from a data-container, performs a mathematical operation on the data and writes the results to another data-container.

In most experiments the analysis block is executed in a loop, so the experiment data is analysed as fast as possible. However, if you need to aquire a certain amount of data first (mostly when recording from the microphone) or if the results only change if the user changes a parameter, you can define the attributes sleep, dynamicSleep and/or onUserInput to pause the analysis loop. Additionally, you can set optimization to only execute analysis modules when their input buffers have changed (see below for details).

sleep
The minimum time in seconds before the whole analysis block is executed again after the last execution has finished. Decimal values allowed.
optional, default: '0.0' (immediately)
dynamicSleep
The minimum time in seconds before the whole analysis block is executed again after the last execution has finished. This refers to a buffer, so the sleep time can be set by the analysis result. If the buffer is empty, the value from sleep is used instead. Available since phyphox file format 1.5 (phyphox 1.0.7)
optional, default: '0.0' (immediately)
onUserInput
If true, the analysis block will not be executed again unless the user changes the content of an input view.
optional, default: 'false'
optimization
If true, analysis modules are only executed if their input buffers have changed. This is false by default, because this can have some confusing impact. For example, the timer-analysis element does not any input and always needs to be executed, triggering any module using its result. In other cases, the analysis process itself is meant to increment a specific value periodically, which would not happen if a corresponding add module is not executed. So, if you know what you are doing, this option can be used to optimize the performance of an experiment, but if in doubt you should leave it off. Available since phyphox file format 1.7 (phyphox 1.1.0)
optional, default: 'false'
<phyphox version="1.0">
    ...
    <analysis sleep="2.0" dynamicSleep="buffer" onUserInput="false">
        <add>
            <input>Buffer1</input>
            <input type="buffer">Buffer 2</input>
            <output>sumBuffer</output>
        </add>
        <divide>
            <input type="value" as="dividend">1</input>
            <input as="divisor">sumBuffer</input>
            <output>inverseSum</output>
        </divide>
    </analysis>
    ...
</phyphox>

Analysis modules in general

<input type="TYPE" as="AS">BUFFER/VALUE</input>
<output as="AS">BUFFER</output>

Almost all analysis modules take inputs and write their results to an output buffer. All inputs and outputs are defined as input and output tags within the analysis module. While the output always has to be a data-container, the input may also be a floating point value which can be defined by setting the attribute type to value. If type is not set, it defaults to buffer and the given name has to match a data-container. Additionally, the input may be set to the type empty, which is similar to value but represents a constant empty buffer. This only makes sense and is supported for few modules and will be noted there.

Both, inputs and outputs, can be given a specific function by the as attribute. For many modules this attribute can be omitted if it is obvious. For example the add module takes an arbitrary number of inputs in an arbitrary order (a+b equals b+a), but the subtract module needs an explicit mapping for the minuend and the subtrahend (a-b does not equal b-a). Similarly, a single output does not need to be mapped, while multiple outputs (for example value and position of a maximum in the max module) need to be mapped.

Additionally, some analysis modules take parameters that are not dynamically defined, but as an attribute to the analysis module tag. As an example, the threshold module searches the point at which the input values cross a given threshold and the attribute falling can switch it to look for a crossing from larger to smaller values.

input-tag
Attributes for input tags:
as
The mapping of the input to a function
optional or required depending on the module
type
Can be set to buffer or value and indicates whether the content of the the tag is a numeric value or refers to a data-container
optional, default: buffer
clear
false will mean, that the buffer retains its data after reading. If set to false, the buffer is cleared after reading, which can be used to process each dataset from an input only once.
optional, default: true
output-tag
Attributes for output tags:
as
The mapping of the input to a function
optional or required depending on the module
clear
false will mean, that the buffer retains its data (from another module writing to this buffer or from the previous analysis run) and new data is appended. true will clear the buffer first.
optional, default: true

List of analysis modules

The specific mappings, attributes and functionality of the analysis modules are documented on a separate page listing all the analysis modules.

Block: views

The views block may hold one or more view blocks (note: singular), describing the different layout groups (views), from which the user may choose to view the experiment data.

At least one view block is required!

<phyphox version="1.0">
    ...
    <views>
        <view label="Pendulum">
            <value label="Frequency" unit="Hz">
                <input>frequencyBuffer</input>
            </value>
            <edit label="Length" unit="cm" factor="100" signed="false" default="50">
                <output>lengthBuffer</output>
            </edit>
            <info label="Example with user-input" />
        </view>
        <view label="Raw data">
            <graph label="Sensor data x" labelX="Time (s)" labelY="Amplitude">
                <input axis="x">timeBuffer</input>
                <input axis="y">sensorBuffer</input>
            </graph>
        </view>
    </views>
    ...
</phyphox>

Block: view

Each view-block groups display elements to present data to the user. The view block has a single attribute label displayed to the user to identify this view when the user switches views. The label should be short and concise.

label
The name identifying this view. Will be translated if a matching translation string is defined.
required

View-Element: info

<info color="COLOR" label="INFOTEXT" />

The info element does not take any inputs or write to any outputs. It just displays a string defined as the label attribute.

label
The text to be displayed to the user
required
color
The text color as six-digit RGB hex value or a named choice from the phyphox Colors
optional, default: background color, Available since phyphox file format 1.7 (phyphox 1.1.0)

View-Element: separator

<separator color="orange" height="0.1" />

The separator element does not take any inputs or write to any outputs. It just acts as a separator to give a visual aid in grouping other elements. It defaults to a very thin height of 0.1 (in units of text line heights) and a color matching the background color of the experiment screen. To achieve a margin between elements, you should set the height to 1 or to create a narrow line, set the color (as six-digit RGB hex value or a named color from the phyphox Colors) and leave the height at 0.1 - optionally padded b two other separator elements.

color
The color of the whole (rectangular) element as six-digit RGB hex value or a named choice from the phyphox Colors
optional, default: background color
height
The height of the separator in text line heights
optional, default: 0.1

View-Element: value

<value label="LABEL" size="FLOAT" precision="INTEGER" scientific="BOOLEAN" unit="UNIT" factor="FLOAT" color="COLOR">
    <input>BUFFER</input>
    <map min="DOUBLE" max="DOUBLE">STRING</map>
    <map>STRING</map>
</value>

The value element displays a single value to the user. If the input buffer contains more than one value, the latest value will be displayed. The input is defined by a simple input tag within the value block and needs to be a data-container (see above).

Since version 1.5 (phyphox 1.0.7) you can define range mappings with the map-tag. The map tag includes a string which will replace the number and unit that would be displayed otherwise. phyphox will test all mappings in the order they are given and replace the output with the first mapping that applies. A mapping applies if the value to be shown falls in the range given by the attributes min and max (inclusive). min and max can be left out and default to negative and positive infinity. So, a map-tag without any attributes acts as a catch-all case.

label
A label for this element
required
color
The text color as six-digit RGB hex value or a named choice from the phyphox Colors
optional, default: background color, Available since phyphox file format 1.7 (phyphox 1.1.0)
size
The size of the displayed value relative to the default font size. Label and unit will stay at their original size. Available since phyphox file format 1.2 (phyphox 1.0.3)
optional, default: 1
precision
The number of digits after the decimal point.
optional, default: 2
scientific
If set to true, the value will be displayed in scientific notation (1.0e-3 instead of 0.001)
optional, default: false
unit
A unit to be displayed after the value
optional, default: no unit
factor
A factor to be applied to the value before displaying it. This is usually used for unit conversion. Example: The data is in meter, but should be displayed in cm. The factor would be 0.01
optional, default: 1.0

View-Element: graph

<graph label="LABEL" aspectRatio="FLOAT" style="STYLE" partialUpdate="BOOLEAN" history="INTEGER" labelX="LABELX" labelY="LABELY" logX="BOOLEAN" logy="BOOLEAN" xPrecision="INTEGER" yPrecision="INTEGER" minX="0" maxX="0" minY="0" maxY="0" scaleMinX="auto" scaleMaxX="auto" scaleMinY="auto" scaleMaxY="auto" lineWidth="1" color="orange">
    <input axis="x">XBUFFER</input>
    <input axis="y">YBUFFER</input>
</value>

The graph element will show a plot of the YBUFFER data against the XBUFFER data. The input buffers are defined by input tags within the value block and need to be a data-containers (see above). The input tags are linked to the axes with an additional axis attribute to the input tag, which may be x or y. See below for additional option for other graph types.

The resulting graph can be made up of lines (default) or dots (set attribute style to dots) and you can use the history attribute to show a history of plots. (see attriute description below and further below for additional types)

The attributes partialUpdate is used for performance optimization. PartialUpdate should be set to true when the buffer is never changed entirely, but new data is just appended with increasing x values. PartialUpdate will then allow that only this data is transferred in the web-interface to save bandwidth.

label
A label for this element
required
apectRatio
The ratio of the total width of this element to the total height of this element in the view. (Including labels and axes)
optional, default: 3
style
If set to dots, the graph will not connect the values with lines. See below for additional styles introduced with file format 1.7 (phyphox 1.1.0).
optional, default: display lines
partialUpdate
If set to true, this allows optimizations which only work if the data is appended with increasing x values. A typical example is sensor data: Only few new values are added and each data point has a greater timestamp than the previous one. In such cases this should be set to true as it allows the web interface to only transfer these new datapoints.
optional, default: false
history
The number of graphs to be shown. 1 means, that the current data is shown. n means, that n graphs are shown, with n-1 graphs containing the data from the previous update. This attribute only makes sense, when the whole graph is replaced on each analysis cycle and can be used to compare the previous n results within a single graph.
optional, default: 1
labelX
The label of the x axis
optional, default: empty, but you should always label your axes... (Note that since file format 1.7 (phyphox 1.1.0) you should set the unit separately in the attribute unitX)
labelY
The label of the y axis
optional, default: empty, but you should always label your axes... (Note that since file format 1.7 (phyphox 1.1.0) you should set the unit separately in the attribute unitY)
unitX
The unit of the x axis
optional, default: empty, the units will be appended to the label, but are also used to give values of individual data points with correct units Available since phyphox file format 1.7 (phyphox 1.1.0)
unitY
The unit of the y axis
optional, default: empty, the units will be appended to the label, but are also used to give values of individual data points with correct units Available since phyphox file format 1.7 (phyphox 1.1.0)
logX
If set to true, the x axis will be on a logarithmic scale
optional, default: false
logY
If set to true, the y axis will be on a logarithmic scale
optional, default: false
xPrecision
The number of significant digits on the x axis. Available since phyphox file format 1.2 (phyphox 1.0.3)
optional, default: 3
yPrecision
The number of significant digits on the y axis. Available since phyphox file format 1.2 (phyphox 1.0.3)
optional, default: 3
minX
Lowest value on the x axis. Only applied if scaleMinX = fixed
optional, default: 0
maxX
Highest value on the x axis. Only applied if scaleMaxX = fixed
optional, default: 0
minY
Lowest value on the y axis. Only applied if scaleMinY = fixed
optional, default: 0
maxY
Highest value on the y axis. Only applied if scaleMaxY = fixed
optional, default: 0
scaleMinX
Method to scale the minimum of the x axis. auto always scales this value to the minimum of the data set. extend scales to the historic minimum. fixed sets the minimum to minX.
optional, default: auto
scaleMaxX
Method to scale the maximum of the x axis. auto always scales this value to the maximum of the data set. extend scales to the historic maximum. fixed sets the minimum to maxX.
optional, default: auto
scaleMinY
Method to scale the minimum of the y axis. auto always scales this value to the minimum of the data set. extend scales to the historic minimum. fixed sets the minimum to minY.
optional, default: auto
scaleMaxY
Method to scale the maximum of the y axis. auto always scales this value to the maximum of the data set. extend scales to the historic maximum. fixed sets the minimum to maxY.
optional, default: auto
lineWidth
Width of the graph line relative to the default width
optional, default: 1
color
Color of the graph line as six-digit RGB hex value or a named choice from the phyphox Colors
optional, default: phyphox orange

Other graph types

Available since phyphox file format 1.7 (phyphox 1.1.0))

Bar charts

Since file format 1.7, you can also use bar charts by setting style to "hbars" or "vbars" for horizontal or vertical bars, respectively. For bar charts, you also define x and y values as you do for line charts, but the x value represents the left edge of a bar while y represents its height (for horizontal bars, y defines the bottom and x the width). Each bar ends where the next one begins and the last height will not be drawn as it only marks the end of the previous bar. Therefore, to draw 4 bars, you need to provide 5 value pairs.

For bar charts, the line width describes the gap between bars. A line width of 1 means that there is no gap, while a line width of 0.5 means that the bars only occupy 50% of the available width (they will be centered in this space).

Color map charts

File format 1.7 also introduces color map charts (also known as false color plots). These do not plot y values as a function of x values, but z values as a function of x and y. z is encoded as a color and the result is a map of different colors.

So, you need to provide three datasets, "x", "y" and "z". This is done similar to the traditional 2D plots:

<graph label="Fourier Transform" logZ="true" labelX="Frequency" unitX="Hz" labelY="Time" unitY="s" labelZ="FFT Mag" unitZ="a.u." aspectRatio="1" style="map" mapWidth="256" partialUpdate="true">
  <input axis="x">fmap</input>
  <input axis="y">tmap</input>
  <input axis="z">fftmap</input>
</graph>

The example shows the color map plot of the "Audio Spectrum" experiment. "fmap" contributes the frequencies for the x axis, "tmap" the timestamps for the y axis and "fftmap" the amplitudes that define the colors. Note that all three buffers need to provide the same number of values and that their indices need to match. There is no requirement that each value of each row needs to have exactly the same value, so the value has to be provide for every single data point. However, you cannot just provide arbitrarily distributed data point.

The color map creates a lattice from the provided points, which is then colored. For this, an additional paramtere "mapWidth" is set for the graph-Tag, which defines how many data points form a row. The datapoints within this row may be at slightly varied locations which will be displayed correctly (although the remote interface will not show their location correctly), but very large deviations can lead to a distorted image as connection to the next row won't match up. If you need to plot random data pairs, you might want to check our the map analysis module.

Also note, that due to the typical use of such color maps, the attribute "partialUpdate" (see above) now applies to the y axis, which needs to be monotonous instead of the x axis.

The color map plot introduces the following additional attributes:

labelZ
The label of the z axis
optional, default: empty, but you should always label your axes...
logZ
If set to true, the x axis will be on a logarithmic scale
optional, default: false
zPrecision
The number of significant digits on the z axis.
optional, default: 3
minZ
Lowest value on the x axis. Only applied if scaleMinX = fixed
optional, default: 0
maxZ
Highest value on the x axis. Only applied if scaleMaxX = fixed
optional, default: 0
scaleMinZ
Method to scale the minimum of the x axis. auto always scales this value to the minimum of the data set. extend scales to the historic minimum. fixed sets the minimum to minX.
optional, default: auto
scaleMaxZ
Method to scale the maximum of the x axis. auto always scales this value to the maximum of the data set. extend scales to the historic maximum. fixed sets the minimum to maxX.
optional, default: auto
scaleMinZ
Method to scale the minimum of the y axis. auto always scales this value to the minimum of the data set. extend scales to the historic minimum. fixed sets the minimum to minY.
optional, default: auto
scaleMaxZ
Method to scale the maximum of the y axis. auto always scales this value to the maximum of the data set. extend scales to the historic maximum. fixed sets the minimum to maxY.
optional, default: auto
mapWidth
Number of data points per line.
optional, but a color map chart won't work without this.
mapColor[n]
n-th color in the color map
optional, if none are defined, phyphox uses a black-orange-white color gradient

You can also define your own color palette. Phyphox uses a black-orange-white gradient by default, but introducing more colors can be very helpful to improve contrast. Colors a simply defined as a series of colors that are spread across the z range:

<graph label="Normalized history" labelX="distance" unitX="cm" labelY="time" unitY="s" labelZ="A" unitZ="a.u." aspectRatio="1" style="map" mapWidth="1200" mapColor1="000000" mapColor2="0000ff" mapColor3="00ffff" mapColor4="00ff00" mapColor5="ffff00" mapColor6="ff0000" mapColor7="ffffff" partialUpdate="true">
  <input axis="x">distance_map</input>
  <input axis="y">time_map</input>
  <input axis="z">weighted_map</input>
</graph>

This example shows the colorful palette of the sonar experiment.

Multiple graphs

Since file format 1.7 (phyphox 1.1.0) you can also combine multiple graph types (except for the color map). To do so, you can simply define more than one dataset for x and y:

<graph label="Acceleration" labelX="t" unitX="s" labelY="a" unitY="m/s²" partialUpdate="true">
  <input axis="x" color="green">acc_time</input>
  <input axis="y">accX</input>
  <input axis="x" color="blue">acc_time</input>
  <input axis="y">accY</input>
  <input axis="x" color="yellow">acc_time</input>
  <input axis="y">accZ</input>
  <input axis="x" color="white">acc_time</input>
  <input axis="y">acc</input>
</graph>

This example just creates four line charts for the "multi" page of the raw accelerometer experiment. You can define different colors (color attribute), line widths (lineWidth) and plot styles (style as line, dots, vbars or hbars) by applying these attributes to the input tag instead of the graph tag. Here, it does not matter if you define these for the x or y axis, but you should make sure that all inputs are assigned to an axis and that they are ordered correctly.

View-Element: edit

<edit label="LABEL" signed="BOOLEAN" decimal="BOOLEAN" min="FLOAT" max="FLOAT" unit="UNIT" factor="FLOAT" default="FLOAT">
    <output>BUFFER</output>
</value>

The edit element displays an edit box, which takes data from the user and writes it to a buffer. The output is defined by a simple output tag within the value block and needs to be a data-container (see above).

label
A label for this element
required
signed
If set to false the user may not enter negative numbers.
optional, default: true
decimal
If set to false the user may not enter decimal (i.e. non-integer) numbers.
optional, default: true
min
The minimum value allowed. Disable by not setting this attribute. Available from phyphox file format 1.1 (phyphox 1.0.2).
optional, default: disabled
max
The maximum value allowed. Disable by not setting this attribute. Available from phyphox file format 1.1 (phyphox 1.0.2).
optional, default: disabled
unit
A unit to be displayed after the value
optional, default: no unit
factor
A factor to be applied to the value before displaying it. This is usually used for unit conversion. Example: The data is in meter, but should be displayed in cm. The factor would be 0.01
optional, default: no unit
default
The default value of the edit box. The experiment will start with this value.
optional, default: 0.0


View-Element: button

Available since phyphox file format 1.3 (phyphox 1.0.4)

<button label="LABEL">
    <input>BUFFER1</input>
    <output>BUFFER1</output>
    <input type="value">42</input>
    <output>BUFFER2</output>
    <input type="empty" />
    <output>BUFFER3</output>
</button>

The button element displays a simple button, which interacts with the buffers outside the analysis cycle. Whenever the user presses the button, the last value from each inputs (which may be value types or data-containers) is written to each output (the first input is written to the first output, the second to the second and so on). Note, that this does not happen at a certain point during analysis, but between analysis cycles, independent of when the user pushes the button.

Since version 1.4 (phyphox 1.0.6) you may define empty inputs (type="empty"), effectively allowing to clear a buffer when pressing the button.

label
A label for this element
required

Block: export

The export block may hold one or more set blocks, grouping and naming multiple data-containers as a logical unit to be written to a file when the user wants to export the data. The user may choose from these sets and for example select if he wants only the raw data, the analysis results or everything in his exported file.

<phyphox version="1.0">
    ...
    <export>
        <set name="Results">
            <data name="Frequency">frequency</data>
            <data name="Period">period</data>
        </set>
        <set name="Raw data">
            <data name="Time t (s)">accT</data>
            <data name="Acceleration x (m/s²)">accX</data>
            <data name="Acceleration y (m/s²)">accY</data>
            <data name="Acceleration z (m/s²)">accZ</data>
        </set>
    </export>
    ...
</phyphox>

Block: set

The set block will define a group of data-containers to be exported. The attribute name will be shown to the user as he may pick which of the sets should be exported. Also these sets may be represented in the final file. For example a CSV export results in a ZIP file containing a separate CSV files for each set. In another example a Excel export will contain a separate sheet for each set.

Tag: data

<data name="NAME">BUFFER</data>

Within each set, you can define multiple data enties. Each of them maps a data-container to a name displayed to the user. Usually, this name is the column title corresponding to the data in the exported file.

name
A name describing the data
required