Error using xlsread (line 132) File name must be a character vector. Error in Lab1 (line 8) trial_data1= xlsread(Raw_Data(i),1);

I've been writing the code to plot the data for a Lab and I'm using a data structure method but I keep getting an error (in my four loop where I use xlsread to read all the files). The error says that I need Raw_Data(which contains an array of all the files I'm calling) as a character vector, in order for xlsread to work. I'm not sure how to do this and I have tried using Char and other methods but it still won't work. Attached is the code. 'CH0' and 'Ch1' are columns in my excel sheet that contain the data I need.

Raw_Data = {'Hot Water Trial 1.xlsx','Hot Water Trial 2.xlsx','Hot Water Trial 3.xlsx','Room Temp Trial 1.xlsx','Room Temp Trial 2.xlsx','Room Temp Trial 3.xlsx','Ice Water Trial 1.xlsx','Ice Water Trial 2.xlsx','Ice Water Trial 3.xlsx'};
data = struct('CH0',[],'CH1',[]);
for i = 1:length(Raw_Data)
    trial_data1= xlsread(Raw_Data(i),1);
    data(i).CH0=trial_data1(:,3);
    data(i).CH1=trial_data1(:,4);
    data(i).CH0_mean=mean(data(i).CH0);
    data(i).CH1_mean=mean(data(i).CH1);
end

Answer 1

[Stephan]

Hi,

since Raw_data is a cell array use {i} to get the content at i in your for loop:

trial_data1= xlsread(Raw_Data{i},1);

instead of:

trial_data1= xlsread(Raw_Data(i),1);

You can see the difference here:

>> a =  Raw_Data{1}

a =

    'Hot Water Trial 1.xlsx'

>> whos a
  Name      Size            Bytes  Class    Attributes

  a         1x22               44  char               

>> b = Raw_Data(1)

is different to:

b =

  1×1 cell array

    {'Hot Water Trial 1.xlsx'}

>> whos b
  Name      Size            Bytes  Class    Attributes

  b         1x1               156  cell   

Best regards

Stephan

[Muhimbo Karangizi]

Thank you Stephan !

This fixed my problem and will help me in the future with understanding Structs.

[Stephan]

if my answer was useful please accept it.