Heatmap plot temperature vs time

I need to create a heatmap showing the temperature trend as a function of time acquired from ten sensors equally spaced. I have tried to plot it starting from a two columns matrix where the first one is a vector relevant to time while the second one is the corresponding temperature. I have tried with the following code:

heatmap(tbl,'time','temperature','Colormap',redbluecmap);

However, it shows me this error message: The name 'time' is not an accessible property for an instance of class 'matlab.graphics.chart.HeatmapChart'.

How can I fix it?

I should obtain something similar to this:

[Walter Roberson]

What shows up for

class(tbl)
tbl.Properties.VariableNames

Answer 1

[Abderrahim. B]

Hi!

I know what is the issue. You have a timetable not a table and the first column related to time is not considered as variable . Solution: Convert to table

Demo below:

clear
MeasurementTime = datetime({'2015-12-18 08:03:05';'2015-12-18 10:03:17';'2015-12-18 12:03:13'});
Temp = [37.3;39.1;42.3];
Pressure = [30.1;30.03;29.9];
WindSpeed = [13.4;6.5;7.3];
TT = timetable(MeasurementTime,Temp,Pressure,WindSpeed)

TT = 3×3 timetable
      MeasurementTime       Temp    Pressure    WindSpeed
    ____________________    ____    ________    _________

    18-Dec-2015 08:03:05    37.3      30.1        13.4   
    18-Dec-2015 10:03:17    39.1     30.03         6.5   
    18-Dec-2015 12:03:13    42.3      29.9         7.3   

TT = timetable2table(TT) ;
heatmap(TT, "MeasurementTime", "Temp")

[Walter Roberson]

That would give a different error:

MeasurementTime = datetime({'2015-12-18 08:03:05';'2015-12-18 10:03:17';'2015-12-18 12:03:13'});
Temp = [37.3;39.1;42.3];
Pressure = [30.1;30.03;29.9];
WindSpeed = [13.4;6.5;7.3];
TT = timetable(MeasurementTime,Temp,Pressure,WindSpeed)

TT = 3×3 timetable
      MeasurementTime       Temp    Pressure    WindSpeed
    ____________________    ____    ________    _________

    18-Dec-2015 08:03:05    37.3      30.1        13.4   
    18-Dec-2015 10:03:17    39.1     30.03         6.5   
    18-Dec-2015 12:03:13    42.3      29.9         7.3   

heatmap(TT, "MeasurementTime", "Temp")

Error using heatmap
Accessing the time vector in a timetable is not supported.

[Abderrahim. B]

You are right.I did not read carefully the question. Need to edit or remove this answer. Thanks Walter.

[Walter Roberson]

The error they received would be consistent with the possibility that they had previously done

tbl = heatmap(...)
    

and are now trying to do

heatmap(tbl, ...)