how to normalize data between 0 and 1 , each column?

i have data that has 13 column and 194 row. i want to normalize each column between 0 and 1 and i want to use min_max method. what should i do? i don't know matlab a lot. plz help me. thank you.

Answer 1

[Stephen23]

This will normalize each column (assuming no NaN, Inf, or complex):

x = [min(a,[],1);max(a,[],1)]
b = bsxfun(@minus,a,x(1,:));
b = bsxfun(@rdivide,b,diff(x,1,1))

[helia mb]

thank you for answering but your answer is not correct i think. because i want each column separate, max-min it. i think the program you wrote will found max and done it to all matrix. can you help me with it?

[Stephen23]

@helia mb: Perhaps you should actually try my code before deciding what it does.

It does exactly what your question asked for: "i want to normalize each column between 0 and 1"

Here is max and min of each output column, and the first and last few rows too:

>> max(b,[],1)
ans =
   1   1   1   1   1   1   1   1   1   1   1   1   1
>> min(b,[],1)
ans =
   0   0   0   0   0   0   0   0   0   0   0   0   0
>> b
b =
 0.00000   0.03662   0.05483   0.42490   0.51527   0.49898   0.75825   0.07069   0.04295   0.50102   0.24175   0.03286   0.13752
 0.00528   0.04541   0.03632   0.57510   0.49080   0.59731   0.79402   0.06290   0.02609   0.40269   0.20598   0.02739   0.08263
 0.01048   0.04101   0.05626   0.50980   0.53993   0.55680   0.78680   0.06572   0.04141   0.44320   0.21320   0.02427   0.07280
 0.01613   0.06593   0.03987   0.61431   0.42952   0.57716   0.69051   0.07844   0.03759   0.42284   0.30949   0.05244   0.18548
 0.02107   0.02637   0.06624   0.30725   0.41112   0.42447   0.58012   0.07350   0.06826   0.57553   0.41988   0.04930   0.27292
 0.02640   0.04835   0.03560   0.56863   0.49080   0.58489   0.79677   0.06644   0.02531   0.41511   0.20323   0.03131   0.10015
 0.03121   0.01978   0.02991   0.50980   0.44792   0.61299   0.75550   0.04524   0.02455   0.38701   0.24450   0.01331   0.04873
 0.03599   0.01758   0.03205   0.41824   0.46632   0.53990   0.77476   0.05300   0.02455   0.46010   0.22524   0.01958   0.09669
 0.04080   0.01978   0.01923   0.40529   0.40486   0.52300   0.73212   0.05654   0.01840   0.47700   0.26788   0.03131   0.17122
 0.04584   0.03222   0.02919   0.56216   0.50313   0.62195   0.84182   0.05160   0.01689   0.37805   0.15818   0.01331   0.02157
 0.05051   0.01171   0.02848   0.33333   0.41112   0.48025   0.70530   0.05654   0.02761   0.51975   0.29470   0.03052   0.18856
... etc
0.95864   0.04688   0.04344   0.50333   0.49080   0.53746   0.76616   0.07208   0.03375   0.46254   0.23384   0.03756   0.14214
 0.96352   0.02343   0.03987   0.39863   0.44166   0.50835   0.70839   0.06078   0.03605   0.49165   0.29161   0.03131   0.16121
 0.96844   0.02563   0.03062   0.45098   0.46007   0.54703   0.77098   0.05724   0.02379   0.45297   0.22902   0.02505   0.11364
 0.97356   0.03662   0.02705   0.51627   0.43559   0.57288   0.74828   0.06078   0.02301   0.42712   0.25172   0.03209   0.13251
 0.97896   0.05200   0.04771   0.52294   0.46632   0.54072   0.71527   0.07493   0.04141   0.45928   0.28473   0.04383   0.16795
 0.98428   0.04760   0.06410   0.44451   0.46007   0.49002   0.65199   0.07917   0.05982   0.50998   0.34801   0.04930   0.21263
 0.98940   0.03662   0.04628   0.35941   0.45399   0.44605   0.70289   0.07775   0.04141   0.55395   0.29711   0.04852   0.23767
 0.99449   0.03516   0.04060   0.32686   0.45399   0.42264   0.72352   0.07987   0.03529   0.57736   0.27648   0.05087   0.25693
 1.00000   0.05787   0.04060   0.53588   0.47847   0.53726   0.75928   0.07917   0.03221   0.46274   0.24072   0.04695   0.17257

[helia mb]

oh i try it. but i open normalized box by mistake . im really sorry sorry how can i use this new data? can you help me?

[Stephen23]

I have no idea what "i open normalized box" means. If you want to create a box plot, then you can simply do this:

 boxplot(b)

[helia mb]

i really appreciate.....thank you :)))

[helia mb]

i want to use this new normalize data again. what ever thank you