error message 'char'.how to solve?

function [EPClist,data]=extraction_data(Nomfichier)

dummy=importfile(Nomfichier);
j=1;

for i=1:height(dummy)
    if dummy.OperationResult(i)==' Read OK'
        data_raw(j,1)=dummy.Date(i);
        data_raw(j,2)=dummy.EPC(i);
        data_raw(j,3)=dummy.ReadData(i);
        j=j+1;
    end
end

clear dummy
EPClist=unique(data_raw(:,2));
Nb_capteur=length(EPClist);
data=cell(1,Nb_capteur);

for i=1:Nb_capteur
    k=1;
    for j=1:length(data_raw)
        if data_raw(j,2)==EPClist(i)
            %data{i}(k,1)=data_raw(j,1);
            %data{i}(k,1)=0;
            data{i}(k,1)=hex2dec(data_raw{j,3}(5:8));
            temphexa=data_raw{j,3}(9:12);
            if temphexa(1)=='F'
                data{i}(k,2)=1/100*(hex2dec(temphexa)-hex2dec('FFFF')+1);
            else
                data{i}(k,2)=1/100*hex2dec(temphexa);
            end
            k=k+1;
        end
    end 
    EPClist{i}=EPClist{i}(end-3:end);
end

Error message:

Undefined function 'importfile' for input arguments of type 'char'.

Error in extraction_data (line 3)

dummy=importfile(Nomfichier);

Error in detect_palier (line 3)

[EPC,B]=extraction_data(titre);

Error in extract_palier (line 23)

[EPC,pression,temperature]=detect_palier(titre,table_delete);

[Luca Ferro]

importfile is not a matlab built-in function, could you share its code or where you have taken it from?

Answer 1

[Walter Roberson]

The function importdata has an option to generate a function that will import other files using the same configuration. It is common for the generated function to be called importfile . But it is not part of MATLAB; it is the result of someone using importdata() and asking to save the associated code.

These days, looking at the imported data, you should probably instead use readtable

[md sazzad]

Hello,

Sorry i dont understand. and i cant do with read table. because in that case i need change all other part of my program. i can not do this bacause of my work law.

could you please do any solution by this program?

[Walter Roberson]

Your existing for i=1:height(dummy) loop would be fine if you were to use readtable, with the exception that you should change the test to

if dummy.OperationResult(i)==" Read OK"

[Walter Roberson]

Rewriting to use readtable:

function [EPClist,data]=extraction_data(Nomfichier)

dummy = readtable(Nomfichier);
j=1;

for i=1:height(dummy)
    if strtrim(dummy.OperationResult(i)) == "Read OK"
        data_raw(j,1)=dummy.Date(i);
        data_raw(j,2)=dummy.EPC(i);
        data_raw(j,3)=dummy.ReadData(i);
        j=j+1;
    end
end

clear dummy
EPClist=unique(data_raw(:,2));
Nb_capteur=length(EPClist);
data=cell(1,Nb_capteur);

for i=1:Nb_capteur
    k=1;
    for j=1:length(data_raw)
        if data_raw(j,2)==EPClist(i)
            %data{i}(k,1)=data_raw(j,1);
            %data{i}(k,1)=0;
            data{i}(k,1)=hex2dec(data_raw{j,3}(5:8));
            temphexa=data_raw{j,3}(9:12);
            if temphexa(1)=='F'
                data{i}(k,2)=1/100*(hex2dec(temphexa)-hex2dec('FFFF')+1);
            else
                data{i}(k,2)=1/100*hex2dec(temphexa);
            end
            k=k+1;
        end
    end 
    EPClist{i}=EPClist{i}(end-3:end);
end

This has three differences compared to your original:

• changed importfile() to readtable()
• changed ' Read OK' to "Read OK"
• added strtrim()

I wanted to account for the possibility that when you used readtable() that possibly the leading space in ' Read OK' might not be present. Either way, whether it is or is not present, this code should work.

There is one potential problem, though: with readtable() the Date might be read as a datetime object rather than as numeric; if so then you would not be able to mix it in with numeric objects. But possibly it will come across as a char vector or as a cell array of char vectors or as a string... it would be easier if we had an extract of a file to test with.

[md sazzad]

function [EPClist,data]=extraction_data(Nomfichier)
dummy = readtable(Nomfichier);
j=1;
for i=1:height(dummy)
    if strtrim(dummy.OperationResult(i)) == "Read OK"
        data_raw(j,1)=dummy.Date(i);
        data_raw(j,2)=dummy.EPC(i);
        data_raw(j,3)=dummy.ReadData(i);
        j=j+1;
    end
end
clear dummy
EPClist=unique(data_raw(:,2));
Nb_capteur=length(EPClist);
data=cell(1,Nb_capteur);
for i=1:Nb_capteur
    k=1;
    for j=1:length(data_raw)
        if data_raw(j,2)==EPClist(i)
            %data{i}(k,1)=data_raw(j,1);
            %data{i}(k,1)=0;
            data{i}(k,1)=hex2dec(data_raw{j,3}(5:8));
            temphexa=data_raw{j,3}(9:12);
            if temphexa(1)=='F'
                data{i}(k,2)=1/100*(hex2dec(temphexa)-hex2dec('FFFF')+1);
            else
                data{i}(k,2)=1/100*hex2dec(temphexa);
            end
            k=k+1;
        end
    end 
    EPClist{i}=EPClist{i}(end-3:end);
end

Here i copy paste totally your program and it shows this error :

>> extraction_data1

Not enough input arguments.

Error in extraction_data1 (line 2)

dummy = readtable(Nomfichier);

[md sazzad]

it is resolved. Thank you

[Walter Roberson]

You have to pass in a file name.