plot X Y grid points V's colour. Real time

[00moz]

Hi, Im now in LV6.1 (upgraded). I can plot x, y grid points v's a third variable Z (represented as colour) using an xy plot with attribute node and buffer fn. But all the points change colour each time the graph updates. Is there ANY way to plot XY gridpoints each having a colour determined by a third variable AND the points to stay there with their original colour WHILE adding new points???

[Greg_McKaskle2]

> Hi, Im now in LV6.1 (upgraded). I can plot x, y grid points v's a
> third variable Z (represented as colour) using an xy plot with
> attribute node and buffer fn. But all the points change colour each
> time the graph updates. Is there ANY way to plot XY gridpoints each
> having a colour determined by a third variable AND the points to stay
> there with their original colour WHILE adding new points???
>

There are a couple options. If there is a limit to the number of points
you want to display, then you can do this with the XY graph by adding a
new plot for each point rather than adding a new point to a single plot.

The other option is to use the picture control. There are examples in
the examples/picture directory for drawing XY graphs with lines
or just
points. The VI can easily be changed to draw the grid once, then draw
new points on top. You can turn off the erase first option on the
picture control, or you can append to the picture in a shift register.
You will easily be able to control the color of each point.

Honestly I think the picture control will be the easier way to do this.

Greg McKaskle

[Randy_H]

OOmoz,

Make sure that you are specifying the correct Active Plot when choosing a new color. If you are just changing the color, then the color of Plot 0 changes. Change the Active Plot first to the correct plot number, then change the color. This can be done in one property node with two property inputs. See the attached picture.

Randy Hoskin
Applications Engineer
National Instruments
http://www.ni.com/ask