Questions on format options and axes tick scaling

[Frank Gansert]

Hi,


I started using octave cause I was in need of minimizing an error for the maximum likelihood method regarding the Weibull distribution.
Everything is running fine, but I want to set the output with respect to a defined variable setting the accuracy in position after decimal point.

I used format long, but that is not what I want and I found format free.

I assumed that format free 4 for example will make an output like x.1234

#test

a = 1.123456789012345

disp("format")

format

a

disp("format short")

format

format short

a

disp("format long")

format

format long

a

disp("format free 1")

format

format free 1

By changing the value of format free nothing happens except that the last number ist cut off.

How does it work or what do I have to do to get a defined output in positions after decimal point?

Another thing that I want to set, regarding the Weibull distribution, is to get proper tickscaling along the axes for the common drawing ln(ln(1/(1-P_f))) with respect to ln(s).

s meaning the stress at failure and P_f the probability for that failure stress.

The scaling for x-Axis is fine but at the y-Axis I want to read the probability of failure in percent with the scaling as above being ln(ln(1/(1-P_f))) so that the CDF is linearized.

I did this in latex using pstricks and placing the ticks manually but as obvious I want some automated graphs.

I am using qtoctave and octave itself in version 3.2.4

I hope anyone can help.

Thanks in advance

Frank