Error when interpolating data code attached

Im getting an error using the interp1, the workspace is attached. I think the issue is with te, where it jumps suddenly at indices 5139-5140. te is a time vector, eth is a concentration

    ethi = interp1 (te, eth, (tg+5))

[Image Analyst]

http://www.mathworks.com/matlabcentral/answers/6200-tutorial-how-to-ask-a-question-on-answers-and-get-a-fast-answer

We can't run anything because you forgot to attach your code. I have no idea what te, eth, and tg are. Give us their values.

[shobhit mehrotra]

te: time for mass spectrometer

tg: gps time

eth: concentration of ethane (parts per billion)

[shobhit mehrotra]

the code and workspace are attached Thank You!

Answer 1

[per isakson]

I get an error when I run your code

    >> ethi = interp1 (te, eth, (tg+5));
    Error using griddedInterpolant
    The grid vectors are not strictly monotonic increasing.
    Error in interp1 (line 191)
            F = griddedInterpolant(X,V,method);

The message, The grid vectors are not strictly monotonic increasing., is clear enough.

    >> issorted( te )
    ans =
         1
    >> issorted( tg )
    ans =
         1

so far so good

    >> any(diff(te)==0)
    ans =
         1
    >> any(diff(tg)==0)
    ans =
         0

Thus, te is not strictly monotonic

    >> find(diff(te)==0)
    ans =
           11034
    >> te(11032:11036)'
    ans =
       1.0e+09 *
        1.4164    1.4164    1.4164    1.4164    1.4164
    >> format hex
    >> te(11033:11036)'
    ans =
       41d51b408950b780   41d51b408950be0e   41d51b408950be0e   41d51b408950c49c
    >> 

    >> figure, plot( te(11030:11040) )

&nbsp

&nbsp

Did you get the same or a different error message?

&nbsp

This works

    >> te(11034)= te(11035)-eps(te(11035));
    >> ethi = interp1 (te, eth, (tg+5));

    >> te(11033:11036)'
    ans =
       41d51b408950b780   41d51b408950be0d   41d51b408950be0e   41d51b408950c49c