How to set the plot start to zero ? I have some measurements. On the x label, they start from 0 to 6, but from 1 I can see something change on

Question

Shimelis Abebe 2021-7-8

1
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/874893-how-to-set-the-plot-start-to-zero-i-have-some-measurements-on-the-x-label-they-start-from-0-to-6

回答： Paul Hoffrichter 2021-7-12

采纳的回答： Paul Hoffrichter

8 个评论
显示 6更早的评论隐藏 6更早的评论

Shimelis Abebe 2021-7-10

在 MATLAB Online 中打开

Dear Paul Hoffrichter thank you very much and I appreciate any time you give me.
Could please share your email address? here is my email address shmels.gabe@wu.edu.et
Kind regards,
Shimelis.

Paul Hoffrichter 2021-7-10

Dear Shimelis, I am assuming that you wish to discuss this problem further and need additional assistance. Since my time is extremely limited due to work and study obligations, I hope you will ask another question. As a community, we will all take a look and try to help you further.

Best Regards, Paul

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Paul Hoffrichter 2021-7-9

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/874893-how-to-set-the-plot-start-to-zero-i-have-some-measurements-on-the-x-label-they-start-from-0-to-6#answer_743598

编辑：Paul Hoffrichter 2021-7-9

在 MATLAB Online 中打开

Here is some made up data to illustrate one approach:

x = [ 0 1.1 2 3.3 5.12];

y = [146 145.9 145.8 139 128;

133 132.8 132 114 133;

119 118 116 102 133 ];

plot(x, y, '-bo')

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

Answer 2

Sean Brennan 2021-7-9

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/874893-how-to-set-the-plot-start-to-zero-i-have-some-measurements-on-the-x-label-they-start-from-0-to-6#answer_743533

在 MATLAB Online 中打开

Like the previous answer said: be sure to plot x values AND y values. MATLAB allows you to plot data in the form:

data = rand(10,1); % Create 10 random points
plot(data); % Plot ONLY the y values - the x-values default to the indices of y

But this plots the data versus its index, in this case from 1 to 10. Yes, this is confusing because the plotting works, but the x-values are missing!

The plot command is normally used with x AND y values. For example, let's say the x-axis values associated with the data are from 0.1 to 1, incrementing by 0.1. Then we can plot the results as:

% Create a column of x data starting at 0.1 up to 1, 
% incrementing by 0.1 (the ' symbol converts the row data to column)
xdata = (0.1:0.1:1)'; 
% Create the random y data column using the rand command
ydata = rand(10,1)
% Plot x versus y
plot(xdata,ydata);

You can modify the plot command, specify a figure, etc. Type "help plot" to learn more about this powerful and probably most often used MATLAB command.

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

Answer 3

dpb 2021-7-9

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/874893-how-to-set-the-plot-start-to-zero-i-have-some-measurements-on-the-x-label-they-start-from-0-to-6#answer_743588

在 MATLAB Online 中打开

x=[0:size(Throughput,2)-1].';           % generate temporary x vector for convenience from 0
hL=plot(x,1E-6*Throughput(1:4,;).');    % plot first four rows of array as columns 

salt to suit.

If there are only 4 rows in Throughput, then can dispense with the indexing expression entirely.

plot() will treat each column in the Y argument if an array as a separate variable; hence the transpose. Saves the explicit reference to have to plot each individually.

See the documentation for plot for all the syntax options; saving the line handles in hL lets you adjust line properties as desired.

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

Answer 4

Shimelis Abebe 2021-7-9

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/874893-how-to-set-the-plot-start-to-zero-i-have-some-measurements-on-the-x-label-they-start-from-0-to-6#answer_743663

Thank you very much for your great help me dear all

Dear Mr Paul Hoffrichter based on your lightful answer I try it semmes what I want but still I dis't geat the heart of my problem.

I wrote the code as given bellow image what is my fualt?

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

Answer 5

Paul Hoffrichter 2021-7-12

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/874893-how-to-set-the-plot-start-to-zero-i-have-some-measurements-on-the-x-label-they-start-from-0-to-6#answer_745133

在 MATLAB Online 中打开

First of all, you should be aware that the following two expressions are equivalent:

>> 1:5.12
ans =
     1     2     3     4     5
>> 1:5
ans =
     1     2     3     4     5

Are you just wanting to label the axis from 0:4 instead of 1:5? If so, then this works:

figure(2)
x = 0:4;
plot(x, Throughput./1e6);
legend('0.5 m/s','1 m/s','1.5 m/s','2 m/s');
xlabel('TTT_{W-L} index (0 sec to 5.12 sec)');
ylabel('Throughput)');
axis([0 5 -inf inf]);
hold off
grid on
box on