What information is conveyed by the different colors in Matlab's contourf( ) data plots?

1 回表示 (過去 30 日間)
Hi,
Matlab has a contourf( ) function, which I used a little bit last night to plot the level sets of say,
Z = f(x,y) = x*cos(y)
I called the contour function using one of Mathworks examples, so I used
contourf(X,Y,Z,10)
axis equal
on an evenly-spaced x-y meshgrid.
What do the various colors represent in the contourf( ) plot?
There's no labeling, like, say, a colormap would provide.
My motivation to plot a function's level sets is to then overlay it with plots of convergent sequences xn (maybe with an "x" marker), converging to roots of the function (using some simple methods like gradient-descent and Newton's method that I've been playing with). Namely, I notice that two algorithms may converge to different roots, when starting from the same initial guess -- so I think it would be interesting to visualize this difference and get better intuition for the geometric aspects of various root-finding algorithms.
Thanks,

採用された回答

Abdolkarim Mohammadi
Abdolkarim Mohammadi 2020 年 9 月 24 日
編集済み: Abdolkarim Mohammadi 2020 年 9 月 24 日
You can turn on the ShowText property of the contour, or add the color bar:
x = linspace (-5, 5, 51);
y = linspace (-5, 5, 51);
[X,Y] = meshgrid (x, y);
Z = X .* cos(Y);
contourf (X, Y, Z, 'ShowText', 'on');
colorbar ();
axis ('equal');

その他の回答 (0 件)

カテゴリ

Help Center および File ExchangeContour Plots についてさらに検索

製品


リリース

R2017a

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by