Trace marker size from wave

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Hi,

In the attached graph there is a data wave plotted (on top of an image) as markers only. The color and size of the markers are set by selecting the same data wave in the customize marker dialog ("set as f(z)"). The min and max of the z-range (for both marker size and color) are set to less than the full range of values in the data wave. Marker color behaves as I expected, all points of the wave with values greater than the max setting for the z-range appear to be the same color. However, marker size does not seem to follow this same behavior. I exected that all points with values greater than the max setting would be the same size. Based on the coloring of the markers this is not the case.

Have I misunderstood the intended funtion of the marker size or have I set something incorrectly? Or... something else?

I have attached an image of the graph and the "set as f(z)" dialog showing the settings for the data wave markers.

Thanks,

Jeff
jtigor wrote:
Hi,
Have I misunderstood the intended funtion of the marker size or have I set something incorrectly? Or... something else?


Since marker size is just a number, it can be, and in fact is, extrapolated. The min/max just set the proportionality.

March 2, 2012 at 02:27 pm - Permalink

jtigor wrote:
I exected that all points with values greater than the max setting would be the same size.


This is the f(z) marker size calculation Igor uses:

markerSizeInPoints[p]= min(400,max(1, (zwav[p] - zMin)/(zMax-zMin)*(markerSizeMax-markerSizeMin) + markerSizeMin))

Note that unlike the zColor settings, the dialog has no "before first marker size" or "after last marker size" settings.

So you'll need to limit your zWave accordingly. With your settings, this won't change the f(z) colors you get.

--Jim Prouty
Software Engineer, WaveMetrics, Inc.

March 2, 2012 at 03:14 pm - Permalink

JimProuty wrote:
This is the f(z) marker size calculation Igor uses:

markerSizeInPoints[p]= min(400,max(1, (zwav[p] - zMin)/(zMax-zMin)*(markerSizeMax-markerSizeMin) + markerSizeMin))


Gotcher. Particularly if you meant...

( ( (zwav[p] - zMin) / (zMax-zMin) ) * (markerSizeMax-markerSizeMin) ) + markerSizeMin

Does "min(400,max(1, ... " mean the maximum marker size is 400 and the minimum is 1?

Quote:
Note that unlike the zColor settings, the dialog has no "before first marker size" or "after last marker size" settings.

So you'll need to limit your zWave accordingly. With your settings, this won't change the f(z) colors you get.


Now that I understand, I see that I will have to change the zwave to get the result that I want. Perhaps you would consider adding those settings in the future?

Thanks,

Jeff

March 2, 2012 at 04:52 pm - Permalink

jtigor wrote:
Does "min(400,max(1, ... " mean the maximum marker size is 400 and the minimum is 1?


Yep.

March 2, 2012 at 09:24 pm - Permalink