How do I make a probability plot with data on the y axis and probability on the x axis?

I want to make a plot for flood frequency showing the data on the y axis and probability (normal or other distributions, e.g. Weibull) on the x axis. I have looked at normplot and probplot but they do not appear to have options for plotting probability on the x axis.

Answer 1

[Jeff Miller]

Something like this:

% some random data for an example
nSample = 500;
floodData = rand(nSample,1);

% percentiles/probabilities at which to
% compare predicted and observed distributions:
percentiles = 1:99;

observed = prctile(floodData,percentiles);
predicted = icdf('normal',percentiles/100,0.5,0.1);

plot(predicted,observed)

[Bruce Rhoads]

thanks, but this is note quite what I am looking for. I need the x axis to be a probability scale. Also I am not trying to compare distribution - the exccedence probability (x values) of the observed y values (data) are already known - it is really normplot but with the probabilities on the x axis and the values of the data on the y axis. It is frustrating that in normplot there just isnt an option to switch which axes the data are plotting on.

[Jeff Miller]

Hmmm, still not sure what you want. Maybe this?

predicted2 = cdf('normal',observed,0.5,0.1);
plot(predicted2,observed)