本檔案是由Maksim從en.wikipedia轉移到維基共享資源。

我，本作品著作权人，释出本作品至公有领域。这适用于全世界。 在一些国家这可能不合法；如果是这样的话，那么： 我无条件地授予任何人以任何目的使用本作品的权利，除非这些条件是法律规定所必需的。

function main() % Subderivative illustration%  set up the plotting window, and some graphing paramenters   figure(1); clf; hold on; axis equal; axis off;   thick_line=2.5; thin_line=2; arrow_size=0.3; arrow_type=1; arrow_angle=20; %(angle in degrees)   font_size=30; ball_rad=0.04;   black=[0, 0, 0]; red=[1, 0, 0];%  define the function; plot the x and y axes and the function   a=-1.5; b=3; h=0.02;    X=[a  0 1 2 3]; Y=[0.3  0.2 0.5 1.5 3];   arrow([a 0],       [b, 0],      thin_line, arrow_size, arrow_angle, arrow_type, black)     arrow([0, min(Y)-1], [0, max(Y)], thin_line, arrow_size, arrow_angle, arrow_type, black);    plot(X, Y, 'linewidth', thick_line);    % the "tangent" lines   x0=X(3); y0=Y(3);   s=0.8; plot(X, s*(X-x0)+y0, 'linewidth', thick_line, 'color', [1, 0, 0])   s=0.5; plot(X, s*(X-x0)+y0, 'linewidth', thick_line, 'color', [1, 0, 0])   % auxiliary line   plot([x0 x0], [0, y0], 'linewidth', thin_line, 'color', [0, 0, 0], 'linestyle', '--')   %  graph some suggestive balls   ball_full (x0, 0, ball_rad, [0 0 0 ]);    ball_full (x0, y0, ball_rad, [1 0 0 ]); %   text, sir   H=text(x0, -0.006*font_size,  'x_0');   set(H, 'fontsize', font_size, 'HorizontalAlignment', 'c', 'VerticalAlignment', 'c')   axis(1.1*[a b min(Y)-1 max(Y)])%  save to postscript   saveas(gcf, 'Subderivative_illustration.eps', 'psc2')   function ball_full(x, y, r, color)   Theta=0:0.1:2*pi;   X=r*cos(Theta)+x;   Y=r*sin(Theta)+y;   H=fill(X, Y, color);   set(H, 'EdgeColor', 'none');  function arrow(start, stop, thickness, arrow_size, sharpness, arrow_type, color)% Function arguments:% start, stop:  start and end coordinates of arrow, vectors of size 2% thickness:    thickness of arrow stick% arrow_size:   the size of the two sides of the angle in this picture ->% sharpness:    angle between the arrow stick and arrow side, in degrees% arrow_type:   1 for filled arrow, otherwise the arrow will be just two segments% color:        arrow color, a vector of length three with values in [0, 1]   % convert to complex numbers   i=sqrt(-1);   start=start(1)+i*start(2); stop=stop(1)+i*stop(2);   rotate_angle=exp(i*pi*sharpness/180);% points making up the arrow tip (besides the "stop" point)   point1 = stop - (arrow_size*rotate_angle)*(stop-start)/abs(stop-start);   point2 = stop - (arrow_size/rotate_angle)*(stop-start)/abs(stop-start);   if arrow_type==1 % filled arrow      % plot the stick, but not till the end, looks bad      t=0.5*arrow_size*cos(pi*sharpness/180)/abs(stop-start); stop1=t*start+(1-t)*stop;      plot(real([start, stop1]), imag([start, stop1]), 'LineWidth', thickness, 'Color', color);      % fill the arrow      H=fill(real([stop, point1, point2]), imag([stop, point1, point2]), color);      set(H, 'EdgeColor', 'none')         else % two-segment arrow      plot(real([start, stop]), imag([start, stop]),   'LineWidth', thickness, 'Color', color);       plot(real([stop, point1]), imag([stop, point1]), 'LineWidth', thickness, 'Color', color);      plot(real([stop, point2]), imag([stop, point2]), 'LineWidth', thickness, 'Color', color);   end

Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version.

Click on date to download the file or see the image uploaded on that date.

• (del) (cur) 20:04, 18 December 2005 . . en:User:Oleg_Alexandrov Oleg Alexandrov ( en:User_talk:Oleg_Alexandrov Talk) . . 540x463 (21025 bytes)

此math图片可使用矢量图形重新创建为SVG文件。这具有很多好处；更多信息请参见共享资源:待清理媒体。如果存在此图片的SVG格式，请将其上传，然后将此模板替换为{{vector version available|新图片名称}}。 建议您将SVG命名为“Subderivative illustration.svg”，这样在使用Vector version available（或Vva）模板时就不需要填写新图片名称参数。