Plot 3d.m

Volume isosurface plotting utility with non-linear adaptive surface spacing. The function plots the 3D volume and the three projections onto the coordinate planes.

Syntax

    plot_3d(spin_system,spectrum,parameters,nsurf,delta,k,signs)

Arguments

    spectrum     - a real cube containing the 3D NMR spectrum

    parameters.sweep       -  three sweep widths, Hz

    parameters.spins       -  cell array with three character
                              strings specifying the working 
                              spins.

    parameters.offset      -  three transmitter offsets, Hz

    parameters.axis_units  -  axis units ('ppm','Hz','Gauss')

    nsurf     - the number of surfaces, a reasonable value is 20

    delta     - minimum and maximum elevation (as a fraction of the
                total intensity) of the surfaces above the baseline.
                A good starting value is [0.02 0.2 0.02 0.2]. The
                first pair of numbers refers to the positive surfa-
                ces and the second pair to the negative ones.

    k    - a coefficient that controls the curvature of the surface
           spacing function: k=1 corresponds to linear spacing and
           k>1 bends the spacing curve to increase the sampling den-
           sity near the baseline. A reasonable value is 2.

    signs   - can be set to 'positive', 'negative' or 'both' - this
              will cause the corresponding surfaces to be plotted.

Outputs

    this function creates a figure

Notes

The following functions are used to compute surface levels:

 cont_levs_pos=delta(2)*smax*linspace(0,1,ncont).^k+smax*delta(1);
 cont_levs_neg=delta(2)*smin*linspace(0,1,ncont).^k+smin*delta(1);

where smin and smax are computed from the spectrum cube.

See also

plot_1d.m, plot_2d.m, volplot.m, molplot.m, mri_2d_plot.m, slice_2d.m

Version 2.3, authors: Ilya Kuprov