使用subplot(row, col, i)建立的子圖，matlab會隱式地調整它們的間距以及它們和整個figure的邊距，以達到它所認為的美觀或者合理的設定，然而如果我們想根據需求設定合理的間距以及邊距，該怎麼定製呢？

這裡提供一個函式（是在沒必要把時間花費在這種繁瑣的格式上）：

function ha = tight_subplot(Nh, Nw, gap, marg_h, marg_w)

% tight_subplot creates "subplot" axes with adjustable gaps and margins
%
% ha = tight_subplot(Nh, Nw, gap, marg_h, marg_w)
%
%   in:  Nh      number of axes in hight (vertical direction)
%        Nw      number of axes in width (horizontaldirection)
%        gap     gaps between the axes in normalized units (0...1)
%                   or [gap_h gap_w] for different gaps in height and width 
%        marg_h  margins in height in normalized units (0...1)
%                   or [lower upper] for different lower and upper margins 
%        marg_w  margins in width in normalized units (0...1)
%                   or [left right] for different left and right margins 
%
%  out:  ha     array of handles of the axes objects
%                   starting from upper left corner, going row-wise as in
%                   going row-wise as in
%
%  Example: ha = tight_subplot(3,2,[.01 .03],[.1 .01],[.01 .01])
%           for ii = 1:6; axes(ha(ii)); plot(randn(10,ii)); end
%           set(ha(1:4),'XTickLabel',''); set(ha,'YTickLabel','')

% Pekka Kumpulainen 20.6.2010   @tut.fi
% Tampere University of Technology / Automation Science and Engineering


if nargin<3; gap = .02; end
if nargin<4 || isempty(marg_h); marg_h = .05; end
if nargin<5; marg_w = .05; end

if numel(gap)==1; 
    gap = [gap gap];
end
if numel(marg_w)==1; 
    marg_w = [marg_w marg_w];
end
if numel(marg_h)==1; 
    marg_h = [marg_h marg_h];
end

axh = (1-sum(marg_h)-(Nh-1)*gap(1))/Nh; 
axw = (1-sum(marg_w)-(Nw-1)*gap(2))/Nw;

py = 1-marg_h(2)-axh; 

ha = zeros(Nh*Nw,1);
ii = 0;
for ih = 1:Nh
    px = marg_w(1);

    for ix = 1:Nw
        ii = ii+1;
        ha(ii) = axes('Units','normalized', ...
            'Position',[px py axw axh], ...
            'XTickLabel','', ...
            'YTickLabel','');
        px = px+axw+gap(2);
    end
    py = py-axh-gap(1);
end

tight\_subplot(Nh, Nw, gap, marg\_h, marg_w)
我們先來介紹引數的含義：Nh, Nw用法同subplot(row, col)表示行數和列數，gap（如[0.01, 0.1]）表示子圖之間垂直方向和水平方向的間隔，marg_h表示的是全部子圖到figure上下邊界的距離，marg_w則表示的是全部子圖到figure左右邊界的距離。

一個例項：

ha = tight_subplot(3,2,[.01 .03],[.1 .01],[.01 .01])
for ii = 1:6; 
    axes(ha(ii)); 
    plot(randn(10,ii)); 
end
set(ha(1:4),'XTickLabel',''); 
set(ha,'YTickLabel','')

如果不是plot繪製的影象，而是imshow()顯示的影象資訊，使用也是如此，

• 建立全部子圖的控制程式碼，hs = tight_subplot(N, N)

• 用子圖各自的控制程式碼建立各自的座標軸，axes(hs(i))

• 在每個座標軸上顯示影象資訊，imshow()

N
hs = tight_subplot(N, N, [0.01, 0.01], [0.01, 0.01], [0.01, 0.01]);
for i = 1:N*N,
    axes(hs(i));
    imshow(...);
end

References

[1] <tight_subplot>

[2] Matlab中控制影象顯示邊界，subplot間距等