[Scilab-users] Multiple regression on semi-log plot

[arctica1963]

Hello,

Thanks for the idea and suggestions. Not too sure how to apply it, if you
could give some pointers on the attached data and code. The ultimate idea is
to get the slopes of the straight line segments. Many thanks, Lester

clear
clf()
// Read data - wavelength (in km)), power, 1 standard deviation
// Unknown data length; 3 columns -default space delimited

// PSD_wavelength.dat from GMT grdfft radially averaged power spectra

data = read('PSD_wavelength.dat',-1,3);

wavelength = data(:,1);
power = data(:,2);
std_dev1 = data(:,3);

ln_power = log(power);

wavenumber = 1./wavelength;
f=gcf();

//plot(wavenumber, ln_power)

scatter(wavenumber, ln_power,'marker','.')

a=gce().children;
a.mark_mode = "on"
a.mark_style = 0
a.mark_size_unit = "point"
a.mark_size=3

xlabel ('wavenumber k (km-1)')
ylabel ('Log (Power)')

PSD_wavelength.dat
<http://mailinglists.scilab.org/file/t495709/PSD_wavelength.dat>  



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