Error message when attempting to plot selected area from a XLSX file: " Specify one or two table subscripts after the table."

Hi, I try to plot a defined area of data in an XLSX file, the area is defined from by the columns C11-C6796 and D11-D6796

So I define the upper left corner by C11 and the lower right corner by D6796. Which I then want to plot, but with

T=readtable('tempDataTrollhFlygpl.xlsx',Range="C11:D6796",ReadVariableNames=false);
plot(T)
xlabel('Year');
ylabel('Temperature');

I get

"Error using plot

Invalid number of input arguments. Specify one or two table subscripts after the table.

Error in uppgift32 (line 2)"

So the error is in the T part of the plot command? I used the MATLAB documentation to define the specific area of data to go in a 2D plot, but why does not that work?

Thanks

Answer 1

[Cris LaPierre]

What variables in T do you wnat to plot? Since T is a table, you must use one of these syntaxes

• plot(tbl,xvar,yvar)
• plot(tbl,yvar)

[Sergio]

The variables (independent and dependent) are given in the columns of C and D.

C, which is the xvar: is C11-C6796

D, which is the yvar, is D11-D6796

I tried:

T=readtable('tempDataTrollhFlygpl.xlsx',Range="C11:D6796",preserve=true)
plot(T,Var2)
xlabel('Year');
ylabel('Temperature');

Unrecognized function or variable 'Var2'.

Error in uppgift32 (line 2)

plot(T,Var2)

But it is MATLAB that calls it "Var2"

[Voss]

T=readtable('tempDataTrollhFlygpl.xlsx',Range="C11:D6796",ReadVariableNames=false)

T = 6786×2 table
       Var1          Var2  
    ___________    ________

    01-Jan-1961    {'0.1' }
    02-Jan-1961    {'0.7' }
    03-Jan-1961    {'1.0' }
    04-Jan-1961    {'0.4' }
    05-Jan-1961    {'0.0' }
    06-Jan-1961    {'0.2' }
    07-Jan-1961    {'0.0' }
    08-Jan-1961    {'-1.1'}
    09-Jan-1961    {'-1.1'}
    10-Jan-1961    {'-0.8'}
    11-Jan-1961    {'-5.4'}
    12-Jan-1961    {'-6.8'}
    13-Jan-1961    {'2.6' }
    14-Jan-1961    {'0.3' }
    15-Jan-1961    {'2.5' }
    16-Jan-1961    {'-2.7'}

plot(T.Var1,str2double(T.Var2))
xlabel('Year');
ylabel('Temperature');

[Sergio]

Fantastic, Thanks for this!!

[Cris LaPierre]

Your data is being read in as text. Here's another option that demontrates the table syntax.

T=readtable('tempDataTrollhFlygpl.xlsx',Range="C11:D6796",ReadVariableNames=false,TextType="string");
T = convertvars(T,"Var2","double")

T = 6786×2 table
       Var1        Var2
    ___________    ____

    01-Jan-1961     0.1
    02-Jan-1961     0.7
    03-Jan-1961       1
    04-Jan-1961     0.4
    05-Jan-1961       0
    06-Jan-1961     0.2
    07-Jan-1961       0
    08-Jan-1961    -1.1
    09-Jan-1961    -1.1
    10-Jan-1961    -0.8
    11-Jan-1961    -5.4
    12-Jan-1961    -6.8
    13-Jan-1961     2.6
    14-Jan-1961     0.3
    15-Jan-1961     2.5
    16-Jan-1961    -2.7

plot(T,"Var1","Var2")
xlabel('Year');
ylabel('Temperature');