function pitchvel3d(nmat)
%This function plots the pitch, time, velocity. It read in a Midi file using nmat format from the MIDI Toolbox. Arrays are created from the velocity, pitch, and onsets/offsets from the midi structure and plotted on a 3-dimensional graph. The highest velocities are shown in the peaks of the graph, lower velocities are shown as smaller lumps.
% Usage: pitchvel3d(nmat)
%
% Example:
%  nmat=readmidi('test.mid');
%  pitchvel3d(nmat)
%
% The following non-standard files are required to run this function. 
% leastnonzero(array) provided at http://www-scf.usc.edu/~lidavid/ISE575/
% readmid(mid) from MIDI TOOLBOX
% onset(nmat) from MIDI TOOLBOX
% dur(nmat) from MIDI TOOLBOX
% pitch(nmat) from MIDI TOOLBOX
% velocity(nmat) from MIDI TOOLBOX
%
% Also see Pianoroll
%
% Author: David Li, USC
% Email: gemste@yahoo.com
%


	on=onset(nmat,'beat');
	off=on+dur(nmat,'beat');
	totaldur=max(onset(nmat))+ dur(nmat(end,:));

	p=pitch(nmat);


v=velocity(nmat);
if (max(v) == min(v))
    disp('ERROR: No velocity in nmat');
end


% pianoroll(nmat)
% figure

t_int=leastnonzero(off-on)/4;
%t_int=leastnonzero(on(2:end)-off(1:end-1))/4;
%leastnonzero(dur(nmat))/4;
%.25;%min(dur(nmat))/2;
p_int=.25;
p_dist=.25;

pitch_space=leastnonzero(p):p_int/4:max(p); %minimi-2:maksimi+2;
time_space=leastnonzero(on)-t_int:t_int/2:max(max(on),max(off))+t_int;
[pi,ti]=meshgrid(pitch_space,time_space);

t=[min(time_space);min(time_space);max(time_space);max(time_space);
    on;on;off;off;
    on-t_int;on-t_int;off+t_int;off+t_int];

pitch=[min(p)-p_int-1;max(p)+p_int+1;min(p)-p_int-1;max(p)+p_int+1;
    p;p+p_dist;p;p+p_dist;
    p-p_int;p+p_dist+p_int;p-p_int;p+p_dist+p_int];
v0=min(v)-(max(v)-min(v))/5;
velocity=[v0;v0;v0;v0;v;v;v;v;v0*ones(4*length(p),1)];
    
zi=griddata(t,pitch,velocity,ti,pi);

surf(ti,pi,zi,zi) 

zlabel('Velocity')
ylabel('Pitch')
xlabel('Time')
SHADING flat

map=COLORMAP;
%map(1:3,1:3)=0;
mapnew=map;
%mapnew(2:end,:)=1;
mapnew(33:end,:)=mapnew(32:-1:1,:);
%map(1:end-1,:)=0;
%map(end,:)=1;
colormap(mapnew)