Combining Datasets

Ignition
1

Hello,

I have two, single column datasets, that are the same length. One is a series of X values while the other is Y values. I’d like to combine them into a single two column dataset so it can be graphed.

From what I’ve seen it has to be done in script but I can’t seem to get the scripting right.

Any input is appreciated.

Thanks!

2

Try something like this. Obviously you’ll have your own datasets, and not the ones I’ve created in script for the purpose of this example:

toPyDS = system.dataset.toPyDataSet

xDataSet = toPyDS(system.dataset.toDataSet(['x'], [[1],[2],[3]]))
yDataSet = toPyDS(system.dataset.toDataSet(['y'], [[4],[5],[6]]))

xs = [row[0] for row in xDataSet]
ys = [row[0] for row in yDataSet]

rows = zip(xs, ys)
xyDataSet = system.dataset.toDataSet(['x', 'y'], rows)

event.source.parent.getComponent('Table').data = xyDataSet
3

That did exactly what I was looking for. However, when I tie it to a chart it has gives an error. I should have noted earlier that these are being read from an OPC server and are coming in as a string. After I do the split I guess the resulting dataset is all strings and the spaces or string datatype may be causing the chart error? Do I need to do something different with the base datasets?

Chart error: “IllegalArgumentException: Illegal type for X value: class java.lang.String (column ‘x’)”

Background:
I remove the brackets from the string, then do a split on “,” in an expression to get the base dataset.

split(substring({Wavelengths}, 1, indexOf({Wavelengths}, "]")),",")

The resulting data set looks like this:


After running the code Kevin posted my combined dataset:

Thanks again.

4

Casting the x and y values from strings to numbers before zipping may be the answer:

toPyDS = system.dataset.toPyDataSet

xDataSet = toPyDS(system.dataset.toDataSet(['x'], [['1.1'],['2.2'],['3.3']]))
yDataSet = toPyDS(system.dataset.toDataSet(['y'], [['4.4'],['5.5'],['6.6']]))

xs = [float(row[0]) for row in xDataSet]
ys = [float(row[0]) for row in yDataSet]

rows = zip(xs, ys)
xyDataSet = system.dataset.toDataSet(['x', 'y'], rows)

event.source.parent.getComponent('Table').data = xyDataSet
1 Like
5

Perfect! Thanks for the help.