The argument is not modified on return.
The vectors x, y and err_y must have the same length, unless err_y is given as a scalar.
Not changed on exit.
The vectors x, y and err_y must have the same length, unless err_y is given as a scalar.
In the initial estimate, the data points where y\ \≤\ 0 are skipped. If there are many such points which should be taken into account for the fit, then convergence is not guaranteed.
Not changed on exit.
This argument can also be a scalar, which is then used as error for all points. If this argument is a vector, then it must have the same length as x and y.
Not changed on exit.
function = factor slope (\θ+1)\<SUP\>\θ+1\</SUP\>/\Γ(\θ+1) (offset+slope*x)\<SUP\>\θ\</SUP\> e\<SUP\>-(\θ+1)*(offset+slope*x)\</SUP\>i.e. a Polya distribution with argument offset+slope*x and with Polya parameter \θ.
The input values for the terms are used as initial values for the fit if the MANUAL option is used (this is not default). The parameters "offset" and "slope" are fitted if the option FIT is specified, otherwise the values have to be specified on input.
Parameters of which the value on input is to be used, must be of type Number.
All arguments except "offset" and "slope" when using the FIX option, must be modifiable, i.e. it can not be a constant nor an expression.
\√(\χ\²/(#points - #parameters))
This correction factor is equal to 1 if the errors to the data points have been assigned correctly.
These arguments must be modifiable, that is, they can neither be constants nor expressions.
Option | Meaning | Defaults |
---|---|---|
AUTO |
Determine suitable starting values | Default |
EQUAL |
Assume equal weight of all points | Not default |
FIT |
Fit the scale of the distribution | Default |
FIX |
Don't modify the scale parameters | Not default |
MANUAL |
Start from given initial values | Not default |
NOPLOT |
Don't plot the histogram and fit | Default |
NOPRINT |
Don't print details during the fit | Default |
PLOT |
Plot the histogram with fit | Not default |
POISSON |
Assume Poisson errors | Default |
PRINT |
Print details during the fit | Not default |
Notes:
Formatted on 21/01/18 at 16:55.