对数化绘制P值地形图

正常使用topplot绘制P值图是这样的，P值越大，图片越亮

但是因为P值本身的原因，P值需要越小越好，这就需要改变绘图的思路，可以对P值求一个log值再求负数，画在地形图上，就对显著的区域一目了然

分享绘图代码如下

% Written By  Yizhou
% Using the code without proper understanding the code and relevant background
% of EEG may lead to confusion, incorrect data analyses,or misinterpretations
% of results.
% The author assumes NO responsibility for inappropriate or incorrect use
% of this code.
% WX：         17373158786
plog = -log10(P_ttest);
topoplot(plog, EEG.chanlocs,'maplimits',[0 3], 'electrodes' ,'off',   'verbose' ,'off', 'style' ,'map'); % 'electrodes' ,'off',是去除电极点，'style' ,'map'是去除等高线
colorbar('YLim',[0 3], 'YTick',[0,1,2,3],'YTickLabel',{'1','0.1','0.01','0.001'});
title('负性刺激vs中性刺激','fontsize',15); %改变标度为log值