MATLAB Color Points According to Variable

[darkfall13]

I have been tasked with making a plot with a couple variables of available data. I'm to make a normal 2D scatter plot of the data with respect to 2 of the variables given, easy enough. But then I'm supposed to color (from red to blue) each point according to a 3rd variable, which is a derivative of a couple other variables (getting convoluted yet?). When I asked what this is about I was told its supposed to be a spacecraft orbit around a planet, where x-axis is Kurth Phase (a moving Saturn SKR coordinate), y-axis invariant latitude. And the derivative spoken of earlier is supposed to be changes in the magnetic field readings taken with respect to latitude). So that with the end result you will have a line (of points where the data was taken) representing the spacecraft trajectory but colored to indicate how the magnetic field is changing to signify places where there is strong changes or weak changes.

When explained it makes sense to me, but I can't see how I'm supposed to code this. What steps do I take to color individual points according to some color scheme/variable?

 

[darkfall13]

I've been thinking a bit on this and I can see I'll need some sort of variable to define the stepping through different color shades, and to define how many shades I'll be wanting. I see the regular "colorbar" command seems to be the right color scheme. But how do I apply to the individual elements of the plot?

 

[Dr Transport]

Try plotting the points using scatter()...

 

[darkfall13]

Wow as much as I thought that didn't help I didn't realize the scatter function can take a vector for color values, and it automatically creates equal transitions for the spectrum. Thank you so much!

 

[blue_raver22]

To color individual points according to a variable in MATLAB, you can use the "scatter" function with the "c" argument. This allows you to specify a vector of values that correspond to the color of each point in your scatter plot. For example, if your third variable is called "magnetic field changes" and you have a vector of values for this variable called "changes", you can use the following code to create a scatter plot with points colored based on the changes in the magnetic field:

scatter(x,y,[],changes,'filled')

This will create a scatter plot with x and y as the coordinates, an empty vector for the size of the points, and the "changes" vector for the color. You can also specify a color map to have a range of colors from red to blue, such as:

colormap('cool')

This will create a color map ranging from blue to red, with blue representing the lowest values and red representing the highest values. You can also customize the color map to your liking using the "colormap" function.

In summary, to color individual points according to a variable in MATLAB, you will need to use the "scatter" function with the "c" argument and specify a vector of values for the color, along with a color map if desired.