Shaded area

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Wed, 04/15/2015 - 07:55 pm

Can I shade an area in a plot? For example, I would draw a rectangle such that the rectangle is in "pattern" fill mode, but transparent, so that the data points in the background are still seen. I cannot find a way to do it.
You can add two waves to the graph and use 'Fill to next' with a pattern. The order of the traces can then be adjusted so that the pattern is in the back.
For just making the graph look nice this maybe overkill.

April 16, 2015 at 01:45 am - Permalink

Thanks. I find Igor to be powerful when it comes to data analysis and all this stuff, but sometimes I feel small and tiny things are missing. I hope developers will consider this.

April 16, 2015 at 07:35 am - Permalink

Solid color transparency is a feature of the upcoming Igor Pro 7.

We hope to have a beta available in the not too distant future (in geologic terms.)

For now, you can use patterns where the background is transparent. There are limitation though. See this in the What's New in Igor Pro 6.1 help file and click on the links.
Fill patterns as used by draw tools and graph fill modes can use a transparent background to support overlap of different patterns. See Drawing Improvements 6.1 and Graphing Improvements 6.1.


Larry Hutchinson
WaveMetrics
support@WaveMetrics.com

April 16, 2015 at 09:04 am - Permalink

Here is an example experiment using lines and fills. The basic idea is to fill the area below a flat line you draw. This way you can shade in as many different (vertical) regions.
backgroundcoloring.pxp

June 21, 2017 at 08:43 pm - Permalink

geologic wrote:
Here is an example experiment using lines and fills. The basic idea is to fill the area below a flat line you draw. This way you can shade in as many different (vertical) regions.


I wrote a procedure to draw shaded regions around clouds of data points. I'm not sure that this doesn't already exist somewhere. If there's interest, I'll post it as a project.

I used the Catmull-Rom spline that I posted recently as a code snippet to make a smooth curve around the convex hull of the data points. I then figure out the center of mass of the resulting polygon and expand about the center to inset the data. The region is drawn in a drawing layer behind the data, and can be edited with the drawing tools.
shaded regions.png

June 22, 2017 at 06:22 am - Permalink

tony wrote:

I used the Catmull-Rom spline that I posted recently as a code snippet to make a smooth curve around the convex hull of the data points. I then figure out the center of mass of the resulting polygon and expand about the center to inset the data. The region is drawn in a drawing layer behind the data, and can be edited with the drawing tools.


You might want to take a look at ImageTransform with the keyword ccsubdivision.

A.G.
WaveMetrics, Inc.

June 22, 2017 at 06:59 am - Permalink

Igor wrote:


You might want to take a look at ImageTransform with the keyword ccsubdivision.

A.G.
WaveMetrics, Inc.


I did take a look, but lacked sufficient imagination to see how that would help me. My starting point is two waves (x and y coordinates of points).

June 22, 2017 at 09:30 am - Permalink