# set empty line plots with colors associate to the Why? import numpy as npĪx = plt.figure(1).add_subplot(projection='3d') On the contrary, the legend recognizes the command and represent the arrays correctly. But unfortunately, the command to plot the second reference frame with dashed/dotted arrows doesn't works. ![]() Now, I would like to add a second reference frame into the same figure. This was for sure a quite good starting point. Please let me know if I'm not clear in what I'm asking.Thank you a lot. Vector between (x,y) and (x+u, y+v) (where (x, y) and (u,v) are taken asĬoordinates in the axis coordinate system). Way to get quiver(X,Y,U,V) to behave so that the vectors plotted would,įor each coordinate (x,y) and corresponding (u,v), be parallel to the To rotate my vectors to respect the aspect ratio? What's the easiest Looks like you specifically rotate the vectors to match up with mapĬoordinates is that right? Applying to the situation above, do I need In looking at the basemap examples (specifically quiver_demo.py), it What should happen is the arrows should point along the # look like it because the slopes do not respect the aspect ratio of # This is a solution to the differential equation y'=1, but it doesn't Here is a small example, modified from the quiver examples in matplotlib. However, when the aspect ratio is not one, a solution will have aĭifferent slope (because the slope is measured in coordinatesĬorresponding to the axes) than the slope of the arrow. The slope of the solution that passes through (x,y). Of ones and V is a vector of y'(corresponding x and y coordinates), soįor the arrow based at point (x,y), the arrow has slope corresponding to Given the function y'(x,y), I plot a quiver where U is a vector One application I'd like to use it for is direction field plots forįirst order linear differential equations (i.e., y' = some function of xĪnd y). I should have asked more questions and complained less sorry. They might indeed call for a design change.įirst off, in rereading my message, it sounded more abrasive than I I have not looked into quiver behavior with transforms-based projections. ![]() It is possible that quiver needs more modification to work properly and flexibly with the new transforms implementation in fact I know of a bug that this introduced, and I will commit a correction shortly. And you can locate them anywhere you want.īasemap illustrates how quiver can be used with curvilinear coordinates the U and V are adjusted to align the arrows with the coordinates. Note that you have full control over U and V you can make the arrows point any direction you want, and be any length you want. Exactly what is it that you want to do, and don't know how to do with quiver as it is? Please provide a script that illustrates what you think is the problem. ![]() Is there an easy way to get a correct quiver plot (i.e., correct slopes) now if the aspect ratio is not 1? And no, a line version has not been added. No, in this respect it would be no different. Has that happened? I suppose a line version would allow different aspect ratios. There was talk of adding a line version of quiver (as opposed to the patch version there now). But I don't think the design is limiting. The required syntax to use this function is as follows: ax. Creating Matplotlib Quiver Plot In order to create a Quiver Plot the ax.quiver () function is used. No, the design suits my applications: I want to plot arrows indicating ocean current vectors as a function of position in the horizontal, or as a function of depth and time. The Quiver plots are useful for Electrical engineers to visualize electrical potential and for Mechanical engineers to show stress gradients. What is the reason for this design decision? Does it have to do with the arrows distorting if the aspect ratio is not 1? At one time, This seems to make the plot pretty useless if the aspect ratio is not 1, since then the slopes of the arrows do not match up with the coordinate axes. In all cases the arrow aspect ratio is 1, so that if *U*=*V* theĪngle of the arrow on the plot is 45 degrees CCW from the *x*-axis. See, for example, the documentation for quiver: Recently I noticed that the quiver plots all make the arrows as if the plot had aspect ratio 1.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |