Unexpected line colors when saving simple plot

Question

John Mahoney 2014-7-30

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/144123-unexpected-line-colors-when-saving-simple-plot

回答： Star Strider 2014-7-30

I am trying to plot some lines with various shades of gray and find some unexpected results.

Matlab plot window expected: gray figure background y1 gray (invisible against background) y2 gray (barely visible against background) y3 white y4 white

Saved plot expected: same line colors, but against white background instead

Matlab plot observed: same as expected

Saved plot observed: white background - OK y1 not visible - WHY? y2 light gray - OK y3 white on white = not visible - OK y4 black - WHY?

clear all
x = linspace(0,1,100);
y1 = sin(20*x);
y2 = sin(20*x) + 0.5*x;
y3 = x;
y4 = x.^2;
figure
hold on
plot(x, 0*x, 'k');
plot(x, y1, 'color', [0.8, 0.8, 0.8]);
plot(x, y2, 'color', [0.83, 0.83, 0.83]);
plot(x, y3, 'color', [0.999, 0.999, 0.999]);
plot(x, y4, '-w');
axis off
print('-dpng', 'test')