So just call the colormap function that you want to use and pass it the desired number of colors. What if you only want 16 colors? Well, all of the MATLAB colormap functions take an optional input argument specifying the number of colors to use. The final part of ImageAnalyst's comment concerned the number of colors. This is just another convenience for setting the color limits. Then ImageAnalyst asked about the syntax for imagesc and imshow. You can also use caxis to quickly get back to automatic computation of color limits. It's one step shorter than getting the Axes using gca and then setting its CLim property. That's just a convenient way to set the color limits. Is there a way to change Matlab's behavior so that plot sets the x-limits equal to the range of the data by default instead of having to do it manually every time (For example with a flag I. I am aware that xlim(1,1001) exists, but I don't want to add this line every single time I use plot. You can restrict this automatic behavior to a specific axis. axis auto sets MATLAB to its default behavior of computing the current axes' limits automatically, based on the minimum and maximum values of x, y, and z data. ImageAnalyst mentioned the function caxis. Matlab automatically sets the x range to be 1:1200. The returned values are the current axes' XLim, Ylim, and ZLim properties.

Or maybe you want to examine the upper elevations. Let's set the color limits to expand the visible details of the lower elevations. You can set the CLim yourself, though, and that changes the way the color is scaled from the data values. They were automatically computed from the range of the data being plotted. Where did those values come from, though? ax.CLim(1) is the bottom value on the color bar, and ax.Clim(2) is the top value. If you look closely at the color bar in the image plot above, you can see the correspondence between it and the CLim values. One of those properties is CLim ('color limits'), which you can access directly this way: ax.CLim If you run this code interactively, you would see a clickable 'Show all properties' link. The Axes object has a large number of properties, so by default MATLAB shows you just the most commonly used ones. The function gca ('get current axes') returns the Axes object. The Axes object controls many aspects of the plot, including the axes rulers, the ticks, the tick labels, the grid lines, and much more. To investigate CLim, start with imagesc, some elevation data, and a color bar. Good question! Let's have a go at it, starting with CLim. How would one go about that, and using which functions? And you want a colorbar with 16 steps - 16 discrete colors.

For example, let's say your values range from 200 to 35,000, and you want all values less than 1000 to be blue and all values more than 29000 to be red. In response to 'MATLAB image display - autoscaling values with imshow,' MATLAB Answerer Extraordinaire ImageAnalyst posted this comment:Ī discussion of the relationship and interplay of caxis(), CLim, and the values you can pass in inside the brackets to imshow() or imagesc() might be useful.

Matlab xlim min