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4
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1 function contour (z, n, x, y) |
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2 |
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3 # usage: contour (z, n, x, y) |
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4 # |
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5 # See also: plot, semilogx, semilogy, loglog, polar, mesh, contour, |
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6 # bar, stairs, gplot, gsplot, replot, xlabel, ylabel, title |
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7 |
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8 |
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9 if (nargin == 1) |
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10 n = 10; |
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11 endif |
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12 |
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13 if (nargin == 1 || nargin == 2) |
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14 if (is_matrix (z)) |
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15 set nosurface; |
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16 set contour; |
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17 set cntrparam bspline |
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18 command = sprintf ("set cntrparam levels %d", n); |
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19 eval (command); |
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20 set noparametric; |
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21 set view 0, 0, 1.9, 1 |
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22 gsplot z w l 1; |
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23 else |
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24 error ("mesh: argument must be a matrix"); |
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25 endif |
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26 elseif (nargin == 4) |
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27 if (is_vector (x) && is_vector (y) && is_matrix (z)) |
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28 xlen = length (x); |
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29 ylen = length (y); |
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30 if (xlen == rows (z) && ylen == columns (z)) |
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31 if (rows (x) == 1) |
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32 x = x'; |
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33 endif |
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34 len = 3 * ylen; |
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35 zz = zeros (xlen, ylen); |
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36 k = 1; |
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37 for i = 1:3:len |
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38 zz(:,i) = x; |
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39 zz(:,i+1) = y(k) * ones (xlen, 1); |
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40 zz(:,i+2) = z(:,k); |
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41 k++; |
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42 endfor |
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43 set nosurface |
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44 set contour |
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45 set cntrparam bspline |
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46 command = sprintf ("set cntrparam levels %d", n); |
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47 eval (command); |
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48 set parametric; |
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49 set view 0, 0, 1.9, 1 |
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50 gsplot zz w l 1; |
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51 else |
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52 disp ("mesh: rows (z) must be the same as length (x)"); |
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53 error (" and columns (z) must be the same as length (y)"); |
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54 endif |
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55 else |
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56 error ("mesh: x and y must be vectors and z must be a matrix"); |
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57 endif |
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58 else |
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59 error ("usage: mesh (z, levels, x, y)"); |
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60 endif |
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61 |
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62 endfunction |
