relax SVN archive

Fix for the analysis specific API common method _data_init_spin().

The data types are now correctly checked - they are not strings but types.

The relaxation dispersion specific _disassemble_param_vector() method is now functional.

This should allow the minimise user function to complete.

The 'exp_fit' relaxation dispersion model now uses the minfx.grid sparseness argument.

This is used to skip all parts of the grid search belonging to a different exponential curve or
different spin. If the number of curves is N and the number of spins M, the grid size decreases
from inc**(2*N*M) to (inc**2)*N*M. For lots of spins and curves, this is a huge decrease.

Fix for the func_exp_fit() relaxation dispersion target function.

The parameter index was not correctly calculated.

Fix for the relaxation dispersion specific _assemble_scaling_matrix() method.

The values were all inverted - the matrix should hold values on the same order as the parameter
values.

The relaxation dispersion func_exp_fit() target function now uses exponential_2param_neg().

This is from the lib.curve_fit.exponential module.

Typo fix for the new lib.curve_fit.exponential.exponential_2param_neg() function.

Created the new lib.curve_fit.exponential module for exponential curve-fitting.

This contains the single exponential_2param_neg() function which will be used for the relaxation
dispersion target functions. This is based on Sebastien Morin's function exp_2param_neg in
maths_fns.exponential.c in his dormant inversion-recovery branch.

Created the lib.curve_fit package and associated unit tests.

This will be used for holding modules such as for exponential curve-fitting required for the
relaxation dispersion analysis.

Missing import in the target_functions.relax_disp module.