| SPH2TOPO | Convert from a 3-column headplot file in spherical coordinates to a 3-column topoplot file in polar (not cylindrical) coords. Used for topoplot and other 2-d topographic plotting programs. Assumes a spherical coordinate system in which horizontal angles has a range [-180,180] with zero pointing to the right ear. In the output polar coordinate system, zero points to the nose. |
| Usage: | >> [chan_num,angle,radius] = sph2topo(input,shrink_factor); |
| Inputs: | |
input |
[channo,az,horiz] = chan_number, azumith (deg), horiz. angle (deg) When az>0, horiz=0 -> right ear, 90 -> nose When az<0, horiz=0 -> left ear, -90 -> nose |
shrink_factor |
radial scaling factor>=1 (Note: 1 -> plot edge 90 deg az 1.5 -> plot edge is +/-135 deg az {default 1} |
| Outputs: | |
channo |
channel number (as in input) |
angle |
horizontal angle (0 -> nose; 90 -> right ear; -90 -> left ear) |
radius |
arc radius from vertex (Note: 90 deg az -> 0.5/shrink_factor); By convention, radius=0.5 is the outer edge of topoplot. Use shrink_factor>1 to plot chans with abs(az)>90. |
| Author: | Scott Makeig, SCCN/INC/UCSD, La Jolla, 6/12/98 |
| See also: | cart2topo, topo2sph |