plot a graph with 3 variables.

I have this data on excel:

first column is temperature, and first row is voltage, the other data are seconds. How could I plot this table on matlab??? Because I only did plots with two variables and in this case i dont know.

Thanks for your attention.

[Jee Jap Haw]

Is it possible to obtain the equation of the plane ?

Answer 1

[Ilham Hardy]

It depends on which plot type do you want,

e.g.

mesh(x,y,z)
surf(x,y,z)

[jose bernardo]

And how I could read the data? I was trying with this:

[v1]=xlsread(['C:\excelfile.xlsx'],'a1:z10'); %% to read all data.

x=v1(:,1) %%% read the column of time

y=v1(1,:) %%% read the row of voltage

z=v1('b2','z10'); %%% read all the matrix of seconds.

But this message is shown "??? Index exceeds matrix dimensions."

where is the problem??? thanks

[Ilham Hardy]

Say the matrix is located in Excel file test.xlsx at field A1:H9

First, import value

impval = xlsread('test.xlsx','a1:h9');

since the matrix(1,1) {1st column, 1st row} is empty in the excel file matlab will put NaN during the data import see below

>> impval =

NaN    0.6000    0.6250    0.6500    0.6750    0.7000    0.7250    0.7500
25.0000  301.0000  310.0000  319.0000  328.0000  337.0000  346.0000  355.0000
45.0000  302.0000  312.0000  322.0000  332.0000  342.0000  352.0000  362.0000
65.0000  303.0000  314.0000  325.0000  336.0000  347.0000  358.0000  369.0000
85.0000  304.0000  316.0000  328.0000  340.0000  352.0000  364.0000  376.0000
105.0000  305.0000  318.0000  331.0000  344.0000  357.0000  370.0000  383.0000
125.0000  306.0000  320.0000  334.0000  348.0000  362.0000  376.0000  390.0000
145.0000  307.0000  322.0000  337.0000  352.0000  367.0000  382.0000  397.0000
165.0000  308.0000  324.0000  340.0000  356.0000  372.0000  388.0000  404.0000

divide the matrix into three seperate groups

time data

t_data = impval(2:end,1);

>> t_data =

25
45
65
85
105
125
145
165

voltage data

v_data = impval(1,2:end);

>> v_data =

0.6000    0.6250    0.6500    0.6750    0.7000    0.7250    0.7500

matrix data

m_data = impval(2:end,2:end);

>> m_data =

301   310   319   328   337   346   355
302   312   322   332   342   352   362
303   314   325   336   347   358   369
304   316   328   340   352   364   376
305   318   331   344   357   370   383
306   320   334   348   362   376   390
307   322   337   352   367   382   397
308   324   340   356   372   388   404

plot the data accordingly

figure(1)
mesh(v_data,t_data,m_data);
figure(2)
surf(v_data,t_data,m_data);

Answer 2

[David Sanchez]

Use plot3 command:

plot3(x,y,z)

Take a look at

doc plot3

or

help plot3