Importing and reading a .RAW file

Hello!

I am a newbie MATLAB user and need to import/load/read a .RAW file. This portion of code is going into appdesigner and I will be using the data for graphs and such. To start with, I just the command window to see what the import function actually take in:

data = importdata('Sertta_Sample_Data.raw')
data = 
struct with fields:
data: [107×20 double]
textdata: {109×21 cell}

I know that the textdata should be the first 2 rows and then the first 3 columns so I am confused on what 109x21 means. That is my first question, what is this actually importing? Second, is this actually usable to read/graph/etc.? After this, I am writing the following code:

%load the data
            data = importdata('Sertta_Sample_Data_12_17_2020_3_09_03_PM_.raw');
            
            %Check Intramentation
            TS = string(app.InstrumentationListBox.Value);
            
            if TS == "TS-101" 
                %Defines the 2nd column as the timeStr variable, converts it into datenum format, and then converts it into datetime format. 
                dates = datetime(data(1:end-1,1),'Format','MM/dd/yyyy HH:mm:ss.SSS');
                timeStr = data(1:end-1,1);
                timeNum = datenum(timeStr);
                times = datetime(timeNum,'ConvertFrom','datenum','Format','MM/dd/yyyy HH:mm:ss.SSS');
                %Add dates to times since they are both in datetime format
                CombinedDT = dates+timeofday(times);                
                Temp1 = data{1:end-1,2}; %Assuming all files have the same column formats,                 
                plot(CombinedDT,Temp1,CombinedDT);
                datetick('x','dd-mmm hh:MM','keepticks');
                set(gca,'XTickLabelRotation',60);
                grid on         

But am getting an error code of:

Error using datetime (line 659)

Input data must be a numeric array, a string array, a cell array containing character vectors, or a char matrix.

My third question is: Is this just because of how I am loading in the .RAW file? If not, how do I fix this?

Answer 1

[Aditya Shah]

Hi!

Please refer to the following MATLAB Answers post with a similar issue:

https://in.mathworks.com/matlabcentral/answers/473688-importing-raw-files-into-matlab

Answer 2

[Walter Roberson]

            data = importdata('Sertta_Sample_Data_12_17_2020_3_09_03_PM_.raw');

According to your display of the result of importdata(), importdata() is returning a struct with two fields. You need to select the appropriate part of structure, such as

            dates = datetime(data.data(1:end-1,1),'Format','MM/dd/yyyy HH:mm:ss.SSS');