Rescaling time vector in 2d

i have a 2d matrices and i am visualizing them using imagesc; (x vector is time) and the x vector is [1 200] i wand to rescale it to be [-1.4 2.4] and visualizing them new time vector. How to do so?

Answer 1

[Voss]

If I understand correctly, here's how you can rescale a matrix to be from -1.4 to 2.4 instead of from 1 to 200:

A = reshape(1:200,10,20); % a 2D matrix with values from 1 to 200

x = [1 200];
new_x = [-1.4 2.4];

new_A = (A-x(1))./(x(2)-x(1)).*(new_x(2)-new_x(1))+new_x(1);

disp(A); disp(new_A);

     1    11    21    31    41    51    61    71    81    91   101   111   121   131   141   151   161   171   181   191
     2    12    22    32    42    52    62    72    82    92   102   112   122   132   142   152   162   172   182   192
     3    13    23    33    43    53    63    73    83    93   103   113   123   133   143   153   163   173   183   193
     4    14    24    34    44    54    64    74    84    94   104   114   124   134   144   154   164   174   184   194
     5    15    25    35    45    55    65    75    85    95   105   115   125   135   145   155   165   175   185   195
     6    16    26    36    46    56    66    76    86    96   106   116   126   136   146   156   166   176   186   196
     7    17    27    37    47    57    67    77    87    97   107   117   127   137   147   157   167   177   187   197
     8    18    28    38    48    58    68    78    88    98   108   118   128   138   148   158   168   178   188   198
     9    19    29    39    49    59    69    79    89    99   109   119   129   139   149   159   169   179   189   199
    10    20    30    40    50    60    70    80    90   100   110   120   130   140   150   160   170   180   190   200

   -1.4000   -1.2090   -1.0181   -0.8271   -0.6362   -0.4452   -0.2543   -0.0633    0.1276    0.3186    0.5095    0.7005    0.8915    1.0824    1.2734    1.4643    1.6553    1.8462    2.0372    2.2281
   -1.3809   -1.1899   -0.9990   -0.8080   -0.6171   -0.4261   -0.2352   -0.0442    0.1467    0.3377    0.5286    0.7196    0.9106    1.1015    1.2925    1.4834    1.6744    1.8653    2.0563    2.2472
   -1.3618   -1.1709   -0.9799   -0.7889   -0.5980   -0.4070   -0.2161   -0.0251    0.1658    0.3568    0.5477    0.7387    0.9296    1.1206    1.3116    1.5025    1.6935    1.8844    2.0754    2.2663
   -1.3427   -1.1518   -0.9608   -0.7698   -0.5789   -0.3879   -0.1970   -0.0060    0.1849    0.3759    0.5668    0.7578    0.9487    1.1397    1.3307    1.5216    1.7126    1.9035    2.0945    2.2854
   -1.3236   -1.1327   -0.9417   -0.7508   -0.5598   -0.3688   -0.1779    0.0131    0.2040    0.3950    0.5859    0.7769    0.9678    1.1588    1.3497    1.5407    1.7317    1.9226    2.1136    2.3045
   -1.3045   -1.1136   -0.9226   -0.7317   -0.5407   -0.3497   -0.1588    0.0322    0.2231    0.4141    0.6050    0.7960    0.9869    1.1779    1.3688    1.5598    1.7508    1.9417    2.1327    2.3236
   -1.2854   -1.0945   -0.9035   -0.7126   -0.5216   -0.3307   -0.1397    0.0513    0.2422    0.4332    0.6241    0.8151    1.0060    1.1970    1.3879    1.5789    1.7698    1.9608    2.1518    2.3427
   -1.2663   -1.0754   -0.8844   -0.6935   -0.5025   -0.3116   -0.1206    0.0704    0.2613    0.4523    0.6432    0.8342    1.0251    1.2161    1.4070    1.5980    1.7889    1.9799    2.1709    2.3618
   -1.2472   -1.0563   -0.8653   -0.6744   -0.4834   -0.2925   -0.1015    0.0894    0.2804    0.4714    0.6623    0.8533    1.0442    1.2352    1.4261    1.6171    1.8080    1.9990    2.1899    2.3809
   -1.2281   -1.0372   -0.8462   -0.6553   -0.4643   -0.2734   -0.0824    0.1085    0.2995    0.4905    0.6814    0.8724    1.0633    1.2543    1.4452    1.6362    1.8271    2.0181    2.2090    2.4000

It is entirely possible that I do not understand correctly, in which case, can you please clarify what you want to do? Specifically, how is x related to your matrices?

[salim sak]

my matrix is 60*200. and i am using imagesc to visualize this matrix. Every thing is ok with image. i just want change xlim from [1 200] to [-1.4 2.4] without any changes in the image (just as scalling )

[Voss]

Oh, ok. In that case, you can set the XData of the image in imagesc():

imagesc(rand(60,200),'XData',[-1.4 2.4])

[salim sak]

Thank you so much

it was a little that made a big difference