I'm trying to plot .csv file

trying to graph the time series vs variables but it produces an error in the time column, can someone help me, indicating where the error is here please

T = readtable('prueba.csv')

T.Date.Format = 'yyyy-MM-dd';

T.Time.Format = 'HH:mm:ss';

myDatetime = T.Date + timeofday(T.Time)

y1 = T{:,7};

plot(myDatetime,[y1],'r-','lineWidth',1)

When I try to graph I get an error in the line highlighted in bold, tks for your support.

Answer 1

[Star Strider]

The ‘Time’ variable is a duration array, so the timeofday call is not necessary.

Try this —

T1 = readtable('https://www.mathworks.com/matlabcentral/answers/uploaded_files/660400/prueba.csv', 'VariableNamingRule','preserve')

T1 = 78×8 table
    No.       Date         Time      mm      {p}       {t}        {pd}       {q}  
    ___    __________    ________    ___    ______    ______    ________    ______

     1     2021-06-01    00:00:00    615    175.27    77.267      4.9991    784.46
     2     2021-06-01    00:00:05    175    175.39    77.267      9.1318    1104.3
     3     2021-06-01    00:45:35    198     172.1    76.443     0.79982     501.5
     4     2021-06-01    00:45:45    163    171.62    76.914      1.4664    472.85
     5     2021-06-01    01:31:05    195    175.63    75.972       9.665    1070.8
     6     2021-06-01    01:31:15    210     169.3    74.794      6.6655         0
     7     2021-06-01    02:16:35    188    178.07    76.384        -0.3    1021.8
     8     2021-06-01    02:16:45    209    169.43    75.559       3.966         0
     9     2021-06-01    03:02:15    166    177.22    74.617    -0.20002    652.62
    10     2021-06-01    03:02:25    177    170.89     73.91    -0.16669         0
    11     2021-06-01    03:47:45    182     177.7    74.912      3.3327     720.6
    12     2021-06-01    03:47:55    196    178.43    73.675      14.064         0
    13     2021-06-01    04:33:25    186    171.01    75.029    -0.20002    1330.3
    14     2021-06-01    04:33:35    201    175.02    57.951      153.41    3392.7
    15     2021-06-01    05:18:55    180    3.7731    78.504        -0.3         0
    16     2021-06-01    05:19:05    193    4.8685    78.445      27.929    594.22

MyDateTime = T1.Date + T1.Time;
MyDateTime.Format = 'yyyy-MM-dd HH:mm:ss';

T2 = [T1(:,1) table(MyDateTime) T1(:,[4:end])]

T2 = 78×7 table
    No.        MyDateTime         mm      {p}       {t}        {pd}       {q}  
    ___    ___________________    ___    ______    ______    ________    ______

     1     2021-06-01 00:00:00    615    175.27    77.267      4.9991    784.46
     2     2021-06-01 00:00:05    175    175.39    77.267      9.1318    1104.3
     3     2021-06-01 00:45:35    198     172.1    76.443     0.79982     501.5
     4     2021-06-01 00:45:45    163    171.62    76.914      1.4664    472.85
     5     2021-06-01 01:31:05    195    175.63    75.972       9.665    1070.8
     6     2021-06-01 01:31:15    210     169.3    74.794      6.6655         0
     7     2021-06-01 02:16:35    188    178.07    76.384        -0.3    1021.8
     8     2021-06-01 02:16:45    209    169.43    75.559       3.966         0
     9     2021-06-01 03:02:15    166    177.22    74.617    -0.20002    652.62
    10     2021-06-01 03:02:25    177    170.89     73.91    -0.16669         0
    11     2021-06-01 03:47:45    182     177.7    74.912      3.3327     720.6
    12     2021-06-01 03:47:55    196    178.43    73.675      14.064         0
    13     2021-06-01 04:33:25    186    171.01    75.029    -0.20002    1330.3
    14     2021-06-01 04:33:35    201    175.02    57.951      153.41    3392.7
    15     2021-06-01 05:18:55    180    3.7731    78.504        -0.3         0
    16     2021-06-01 05:19:05    193    4.8685    78.445      27.929    594.22

EDIT — (21 Jun 2021 at 19:58)

With respect to the plot —

figure
plot(T2.MyDateTime, T2.('{pd}'), '-r', 'LineWidth',1)
grid

xlabel('Date & Time')
ylabel('\{pd\}')
title('\{pd\} as a function of time')

.

[Willian Alexander Correa Reyes]

Excuse the question, does it have to do with R2017b? Because I have tried to run the script that you have provided and it throws me an error in the console, I have also deleted the 'VariableNamingRule' and 'Preserve', because it did not allow me to continue with the iteration

T1 = readtable('prueba.csv')

MyDateTime = T1.Date + T1.Time;

MyDateTime.Format = 'yyyy-MM-dd HH:mm:ss';

T2 = [T1(:,1) table(MyDateTime) T1(:,[4:end])]

figure

plot(T2.MyDateTime, T2.('{pd}'), '-r', 'LineWidth',1)

grid

xlabel('Date & Time')

ylabel('\{pd\}')

title('\{pd\} as a function of time')

Command Window said:

Error using Untitled4 (line 2)

Addition is not defined between datetime arrays.

Tks

[Star Strider]

There was no release posted, so I assume R2012a. The 'VariableNamingRule' (or variations of it) were introduced after R2017b. Just refer to the variables by their column numbers instead.

In R2021a, the ‘Time’variable is automatically a duration array. Using the time function on the ‘Time’ variable should convert it to a duration array. Try that. If it does, the rest of my code should work.

.