So I am improving my cluster parameters fitting function, and creating my mass fittingfunction, and have a feeling something is wrong. All the code seems right. The cluster parameters returned visually fit the data well. The mass returned is within .1 of the rough distance only mass approximation. But the PDF for the mass is a delta function. I'm pretty sure we can't know the mass to a greater precision than .001 solar masses.
Later on, I have discovered that the PDF and even the maximum is highly dependent on the error. The RMS quoted for the star is .003, but MATLAB won't handle the extremely small probabilities that result from that. And obviously 67% of the bright stars are not .003 within a predicted isochrone. So I used .03, which gives the delta at 2.227, but I move it to .3, and it changes and moves the maximum to 2.5 (part of the loop that it obviously doesn't belong to).
I believe astrophysical properties, and not instrumentation, determine the majority of the error. Thus, I will fit all the clusters, and determine the error from tabulating the distribution of stars around their isochrones.
Note: I just eliminated fainter data since it included many background stars not even close to being on the main sequence, and I used CCD data.
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