how to find max and min value within a certain range of a plot

Question

ZENONG 2023-4-12

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1945839-how-to-find-max-and-min-value-within-a-certain-range-of-a-plot

评论： Star Strider 2023-4-13

Hi, I'm using plot function to identify second wave and measure it's frequency, so is there any way for me to get timeseries of the max and min value within the second wave range directly without have to search them in csv files. Thank you.

2 个评论
显示无隐藏无

Antoni Garcia-Herreros 2023-4-12

Do you havethe mat file?

ZENONG 2023-4-13

tek0000ALL.fig

This is the plot file and want to know how to find the timeseries of first upper peak and second lower peak.

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Star Strider 2023-4-12

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1945839-how-to-find-max-and-min-value-within-a-certain-range-of-a-plot#answer_1214369

Use the bounds function on the specific plot argument.

3 个评论
显示 1更早的评论隐藏 1更早的评论

Star Strider 2023-4-13

在 MATLAB Online 中打开

tek0000ALL.fig

EDIT — (13 Apr 2023 at 17:34)

I am not certain what you want. This provides the peak values, locations, and frequencies of each peak, valley, and complete wave. (The frequencies are not printed on the plot because there is not room enough for them.)

I = openfig('tek0000ALL.fig');

grid

Lines = findobj(I, 'Type','line');

xv = Lines.XData;

yv = Lines.YData;

Tss = [mean(diff(xv)) std(diff(xv)) median(yv)];

Fs = 1/Tss(1);

[pks,plocs] = findpeaks(yv, 'MinPeakProminence',max(yv)/4);

[vys,vlocs] = findpeaks(-yv, 'MinPeakProminence',max(-yv)/4);

zxix = find(diff(sign(yv-median(yv))));

rtbl = find(zxix>max(vlocs),1,'first');

zxix = zxix(1:rtbl);

periodv = diff(xv(zxix));

pervbfr = buffer(periodv,2);

freqv = 1./sum(pervbfr) % Frequency Of Each Complete Wave

freqv = 1×4

1.0e+06 * 0.8039 2.8090 1.2136 0.5869

figure

plot(xv, yv)

hold on

hold off

grid

yline(median(yv))

text(xv(plocs), pks, compose(['(%.2fx10^{-5}, %.3f)'],[xv(plocs)*1E5; pks].') )

text(xv(vlocs), -vys, compose(['(%.2fx10^{-5}, %.3f)'],[xv(vlocs)*1E5; -vys].') )

.

ZENONG 2023-4-13

Thank you!

Star Strider 2023-4-13

As always, my pleasure!

请先登录，再进行评论。

how to find max and min value within a certain range of a plot

2 个评论
显示无隐藏无

采纳的回答

3 个评论
显示 1更早的评论隐藏 1更早的评论

更多回答（0 个）

另请参阅

类别

标签

Community Treasure Hunt

how to find max and min value within a certain range of a plot

2 个评论 显示 无隐藏 无

采纳的回答

3 个评论 显示 1更早的评论隐藏 1更早的评论

更多回答（0 个）

另请参阅

类别

标签

Community Treasure Hunt

WeChat

2 个评论
显示无隐藏无

3 个评论
显示 1更早的评论隐藏 1更早的评论