function?spy2（Acol）
%SPY2?An?improvement?of?SPY
%???SPY2（A）??where?A?is?a?matrix?will?plot
%???the?matrix?with?color?codes.
%???Elements?containing?NaN?or?Inf?will?be?counted?as
%???non-zero?but?will?be?displayed
%???as?zero?elements.
%
%???SPY2（ACOLOR）??will?plot?zero?elements?with
%???white?color?and?nonzero?elements?with?black
%???color.
%???Elements?containing?NaN?or?Inf?will?be?counted?as
%???non-zero?and?will?also?be?displayed
%???as?non-zero?elements.
%
%???The?displayed?matrix?will?have?sides?proportional?to
%???the?number?of?elements?in?each?row/column.
%???If?the?matrix?contains?complex?numbers?only?the?real
%???part?will?be?displayed.
%
%???See?also?SPY.

%?Copyright?2000-11-14?B.?Rasmus?Anthin.
%?Revision?2003-09-15?2003-09-16.

error（nargchk（12nargin））

A=real（double（A））;
A（~isfinite（A））=realmin;
A（end+1end+1）=0;
x=1:size（A2）;
y=1:size（A1）;
[XY]=meshgrid（x-.5y-.5）;???%i?use?surf?and?meshgrid?instead?of?pcolor?so?that
if?nargin==1
???surf（XYA）??????????????????%?the?element?numbers?will?be?correctly?aligned
???colormap?gray????????????????%just?change?this?afterwards?to?get?another?colormap
???colorbar
else
???A=~~A;
???A（1:endend）=0;
???A（end1:end）=0;
???surf（XYA）
???if?ischar（col）
??????switch（lower（col））
??????case?{‘y‘‘yellow‘}
?????????col=[1?1?0];
??????case?{‘m‘‘magenta‘}
?????????col=[1?0?1];
??????case?{‘c‘‘cyan‘}
?????????col=[0?1?1];
??????case?{‘r‘‘red‘}
?????????col=[1?0?0];
??????case?{‘g‘‘green‘}
?????????col=[0?1?0];
??????case?{‘b‘‘blue‘}
?????????col=[0?0?1];
??????case?{‘w‘‘white‘}??????%very?bad?idea?:-）
?????????col=[1?1?1];
??????case?{‘k‘‘black‘}
?????????col=[0?0?0];
??????otherwise
?????????col=[0?0?1];?????????%default?to?blue?color
??????end
???end
???if?isempty（col）?col=[0?0?1];end
???colormap（[1?1?1;col]）
end
view（2）
axis?ij?equal?tight
box?on
xlabel（[‘nz?=?‘?int2str（nnz（A））]）

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----
?????文件????????1946??2018-07-11?20:21??spy2.m