Why are my FrameTicks not working on ArrayPlot?

Question

For some reason the ticks don't work on this:

ArrayPlot[Thread@{Range[0, 1, 0.01]}, AspectRatio -> 4, 
 ColorFunction -> "Rainbow",
 PlotRange -> {{0.`, 1.`}, {0.`, 1.`}},
 FrameTicks -> {{None, {{0, 75}, {1/5, 100}, {2/5, 125}, {3/5, 
      150}, {4/5, 175}, {1, 200}}}, {None, None}},
 Frame -> True,
 PlotRangePadding -> 0,
 BaseStyle -> 
  Directive[Opacity[1], FontFamily -> "Bitstream Charter", 10],
 ImageSize -> {Automatic, 100}]

... interestingly, the way PlotRange works inside ArrayPlot and MatrixPlot is quite different from what we have come to expect based on standard usage patterns inside other Graphics objects. So, instead of removing PlotRange you can also use PlotRange->{All,All,{0.,.1}}. See other interesting examples in the ArrayPlot>>Options>>PlotRange — kglr, Oct 17 '12 at 18:55
@kguler Probably a typo (.1 instead of 1), it should be PlotRange -> {All, All, {0, 1}} — VLC, Oct 17 '12 at 19:35

VLC · Accepted Answer · 2012-10-17T19:34:11.963

6

I think that your problem is related to the fact that your array is actually a vector. If you use Automatic in FrameTicks you get this:

ArrayPlot

But you can apply this workaround:

ArrayPlot[Thread@{Range[0, 1, 0.01]}, AspectRatio -> 4, 
 ColorFunction -> "Rainbow", PlotRange -> {{0.`, 1.`}, {0.`, 1.`}}, 
 FrameTicks -> {{None, {{.5, 75}, {.7, 100}, {.9, 125}, {1.1, 150}, {1.3, 175}, 
 {1.5, 200}}}, {None, None}}, Frame -> True, 
 PlotRangePadding -> 0, 
 BaseStyle -> 
  Directive[Opacity[1], FontFamily -> "Bitstream Charter", 10], 
 ImageSize -> {Automatic, 100}]

ArrayPlot

Update

To get your gradient you have to remove the PlotRange and then specify a new set of ticks.

ArrayPlot[Thread@{Range[0, 1, 0.01]}, AspectRatio -> 4, 
 ColorFunction -> "Rainbow", 
 FrameTicks -> {{None, {{1, 75}, {20, 100}, {40, 125}, {60, 150}, {80,
       175}, {100, 200}}}, {None, None}}, Frame -> True, 
 PlotRangePadding -> 0, 
 BaseStyle -> 
  Directive[Opacity[1], FontFamily -> "Bitstream Charter", 10], 
 ImageSize -> {Automatic, 100}]

ArrayPlot with gradient

edited Oct 17 '12 at 19:34

answered Oct 17 '12 at 17:55

VLC

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But where is the gradient!? – Tom Wellington Oct 17 '12 at 18:05
There should be a vertical rainbow gradient – Tom Wellington Oct 17 '12 at 18:13
@TomWellington Your plot didn't produce any either, so I was dealing with FrameTicks only. – VLC Oct 17 '12 at 18:14
@TomWellington See update for the gradient. – VLC Oct 17 '12 at 18:23
Change {0,75} to {1,75} to get the first tick. – kglr Oct 17 '12 at 18:29
Thanks! @VLC that will work. But what if I wanted the plot range to be from 0 to 1, instead of 0 to 100? – Tom Wellington Oct 17 '12 at 18:37
@TomWellington Your range is defined by the length of your array. If you plot Thread@{Range[0, 1, 0.001]} the range will be between 0 and 1000. – VLC Oct 17 '12 at 19:53
@TomWellington Looking at your plot which is thin and has a vertical gradient with ticks on the right, it looks like you are trying to create a colorbar to use with your plots. If that's the case, I would suggest something simple like in this answer of mine or something like in Jens' answer if you're looking for more customizations. – rm -rf Oct 17 '12 at 20:42

Why are my FrameTicks not working on ArrayPlot?

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