       Re: Problem in generating a DO cycle (mathematica 6.0)

• To: mathgroup at smc.vnet.net
• Subject: [mg95353] Re: Problem in generating a DO cycle (mathematica 6.0)
• From: dh <dh at metrohm.com>
• Date: Fri, 16 Jan 2009 06:10:02 -0500 (EST)
• References: <gkn5jk\$ihb\$1@smc.vnet.net>

```
Hi Valeria,

if I understand correctly, you have a matrix: m and want to change this

into a vector: v, containing the elemnsts of m. In mathematica there are

often easier ways than Do loops. In this case:

Flatten[m]

will return a vector containing the elements of m raw-wise (first

raw,second raw..)

Flatten[Transpose[m]]]

gives a vector column-wise.

hope this helps, Daniel

Valeria Volpe wrote:

> Dear all I have a problem in generating a DO cycle (mathematica 6.0).

>

> Through these commands I acquire a bitmap image from a my folder and create

> a "Graylevels" file:

>

> Quit;

> SetDirectory[ "C:\\Users\\...\\Dati\\\Bitmap\\\xxx"];

> nome = "p6a.bmp";

> Import[nome, "ImageSize"];

> row = ToExpression[Import[nome, "ImageSize"]][];

> col = ToExpression[Import[nome, "ImageSize"]][];

> vmax = row*col;

> gv = Array[f, vmax];

> gl = Import[nome, "GrayLevels"];

>

>

> at this point I have a matrix with all graylevels.

>

> Now my problem is to create a two DO cycle (one for rows and one for

> columns) which allow me to generate an array (gv) whose elements are the

> product row x column of the matrix:

>

> gv[i] = gl [j,k]

>

> where:

> {i,1,Vmax}

> {j,1,row}

> {k,1,col}

>

> Can you pleasa herlp me to generate these Do Cycle?

>

> Thanky

> Vale

>

>

```

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