Custom Size Graphics export doesn't work?

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Thu, 11/14/2013 - 04:15 pm

I have a graph that I would like to export to be 3 inches wide by 1.5 inches tall.

So, since I have trouble with exporting graphics from igor, I use ModifyGraph and make the graph 216 x 108 pixels. I then move the legend around so it's in the correct place, then click "save graphics". I choose PNG (I'm on a mac) and if I just let it stay at "same size" it says 4.04 x 2.15 inches.... Not correct at all. So I choose custom size and put in 3 x 1.5. Ok, great. I up the resolution to whatever I need then save it.

Great.

I then open the picture in preview (on a mac) and look at the image size. It says 2350 x 1244 pixels at 571 pixels/inch. So, do a bit of math.. and that's...4.11 x 2.17.

Weird...

So I go back into igor, export the same graph, but change the custom size to 3 x 1.6. I save the file (different file name), open it up in preview, and look at the size.

It's exactly the same, even though I changed the custom size in the output dialog... Preview still reports 2350x1244. (This error is the same regardless of the resolution options I choose in igor, even if I just use normal resolution, the size reported in preview is 289x155, no where near 218x108...

What gives? Even the command line says the correct values, 218,108, but it doesn't seem to actually export them that size....

Maybe I'm doing this wrong, maybe igor is making the graphs look good on my screen (dumb if you ask me, since everyone's resolutions are different), I'm simply trying to export graphics for a paper, so I want very high resolution as file size doesn't matter, and I want them to be EXACTLY 3x1.5. I don't want to have to resize the afterward because then the text size will be off, and will look different from the rest of the paper.
Oh, and I'm using version 6.32a, on a mac running 10.9.

EDIT: And it does the same thing with TIFF as well.

November 14, 2013 at 04:21 pm - Permalink

Quote:
So, since I have trouble with exporting graphics from igor, I use ModifyGraph and make the graph 216 x 108 pixels. I then move the legend around so it's in the correct place, then click "save graphics". I choose PNG (I'm on a mac) and if I just let it stay at "same size" it says 4.04 x 2.15 inches


ModifyGraph sets the dimensions of the plot area (bounded by the axes). The setting in the Save Graphics dialog sets the overall dimensions of the graphic as a whole, both inside and outside the plot area.

Use MoveWindow instead of ModifyGraph to set to overall size of the graph.
Make jack=sin(x/8)
Display jack
MoveWindow /I 1, 1, 1+3, 1+1.5
SavePICT/E=-5/B=72


I did this and opened the resulting PNG file in Preview. In Preview I chose Tools->Show Inspector. The inspector says the image size is 216 by 108 pixels at 72 dots-per-inch.

I then exported the graph again at 4X resolution using:
SavePICT/E=-5/B=(4*72)


I then opened in Preview. The inspector says it is 864 by 432 pixels which is 4 times as large as before. The inspector also says the DPI is 285.29. (I don't know where it gets that number - it should be 288 DPI.) 864/285.29 = 3.0285 which is 3 inches accurate to one pixel I suspect.

November 14, 2013 at 05:30 pm - Permalink

Thanks a lot! By the time I had left yesterday I figured out that it just set the plot area, so I tried to set the "Margin" of the graph to a specific number, then subtract that number from 218,108. It didn't end up working. Movewindow looks like exactly what I need though, thanks!

EDIT: You must make sure that the size of the plot area is set to "Auto" before you try this, or it won't turn out correctly (rather the plot area won't resize when you resize the window). Just reference for anybody who comes across this later.

November 15, 2013 at 08:35 am - Permalink