918af4f3ac
* change simulator svg * change radio image * Remove google fonts cdn * change color of 'advanced' button * font fix * font fix 2 * display fix * change fullsceen simulator bg * Continuous servo * handle continuous state * adding shims * update rendering for continuous servos * fixing sim * fix sig * typo * fix sim * bump pxt * bump pxt * rerun travis * Input blocks revision - add Button and Pin event types - merge onPinPressed & onPinReleased in new onPinEvent function - create new onButtonEvent function * update input blocks in docs and tests * remove device_pin_release block * Hide DAL.x behind Enum * bring back deprecated blocks, but hide them * shims and locales files * fix input.input. typing * remove buildpr * bump V3 * update simulator aspect ratio * add Loudness Block * revoke loudness block * Adds soundLevel To be replaced by pxt-common-packages when DAL is updated. * Remove P0 & P3 from AnalogPin Co-authored-by: Juri <gitkraken@juriwolf.de>
98 lines
2.4 KiB
Markdown
98 lines
2.4 KiB
Markdown
# Plotting data with LEDs
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To quickly see and record your data values, use the ``||led:plot bar graph||`` block. It will plot a value on the LED screen and write a number to console at the same time.
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```blocks
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basic.forever(() => {
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let i = 0
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while (i < 25) {
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led.plotBarGraph(i, 25)
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i += 2
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basic.pause(1000)
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}
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})
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```
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Here's a plot of values from `1` to `25`:
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```sim
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basic.forever(() => {
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let i = 0
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while (i < 25) {
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led.plotBarGraph(i, 25)
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i += 2
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basic.pause(1000)
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}
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})
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```
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## Plot range
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A number of LEDs will light up to show how much the value is related to the _high_ number in the second argument. The high number sets the _range_ of values to show. If the high number is set to `16` and you want to plot the value of `8`, then that value is half of the range.
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```block
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led.plotBarGraph(8, 16)
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```
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So, about half of the LEDs will light up to represent that number.
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```sim
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basic.forever(() => {
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basic.clearScreen()
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basic.showString("8 up to 16")
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basic.clearScreen()
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basic.pause(500)
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led.plotBarGraph(8, 16)
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basic.pause(2000)
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})
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```
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## Autoranging
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If you don't know what the largest number to plot will be, then you can set the high number to `0`. This lets the largest value plotted be the range value. This is called _autoranging_. To see how it works, make an array of numbers and plot them. Put a large value in the middle of the array with smaller values before and after it. Watch as the same values are plotted with fewer lights after the largest number is plotted.
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```blocks
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let values = [4,8,12,16,50,4,8,12,16]
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for (let i = 0; i < values.length; i++) {
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led.plotBarGraph(values[i], 0)
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basic.pause(1000)
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}
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```
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## Recording plotted values
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The ``||led:plot bar graph||`` also sends the number value it's plotting to the console. You can see the output in the Data Viewer. It charts the values and they appear as individual numbers in console.
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```blocks
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input.onButtonPressed(Button.B, () => {
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for (let i = 0; i < 25; i++) {
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if (i % 2 > 0) {
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led.plotBarGraph(0, 0)
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} else {
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led.plotBarGraph(i, 24)
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}
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basic.pause(500)
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}
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})
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```
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The chart for the the plotted values from the example above:
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The values appear in the console as just one number per line:
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```
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0
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2
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0
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4
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0
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6
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...
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```
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## See also
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[plot bar graph](/reference/led/plot-bar-graph)
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