Help in writing a a code for an array based on comdition.

I have an array A. A1= [-0.0082 -0.0409 -0.0175 -0.0853 0.0217 -0.2556 -0.0302 0 ]

From A array I want to replace negative numbers with -1, positive numbers with 1 and zero will remain zero . Like this :

A= [-1 -1 -1 -1 1 -1 -1 0]

Then I want to take there sum and if there sum is smaller than threshold then value will be set to zero. If equals and greater than threshold than value will be 1. Threshold is 12.

How to write code for this?

Answer 1

[Torsten]

A1 = [-0.0082   -0.0409   -0.0175   -0.0853    0.0217   -0.2556   -0.0302]

A1 = 1×7

-0.0082 -0.0409 -0.0175 -0.0853 0.0217 -0.2556 -0.0302

A = -(A1<0) + (A1>0)

A = 1×7

-1 -1 -1 -1 1 -1 -1

s = sum(A)

s = -5

threshold = 12;
value = double(s >= threshold)

value = 0

[Haya Ali]

How to write zero values as zero in this 'A = -(A1<0) + (A1>0)'?

[Walter Roberson]

A1 = -2:2

A1 = 1×5

-2 -1 0 1 2

A = -(A1<0) + (A1>0)

A = 1×5

-1 -1 0 1 1

So the code already leaves 0 as 0.

[Haya Ali]

It is taking 0 as a positive number and -0 as a negative number. Please help

  Columns 1 through 13

    0.0000   -0.0000    3.2115    2.7009   -0.0000   -0.0000    0.0000    0.1799    0.9524   -0.0000   -0.0000    0.1566    0.0000

  Columns 14 through 25

   -0.0000   -0.0000   -0.0000   -0.0000   -0.0000    0.0000   -0.0000    0.0000   -0.0000    0.0000   -0.0000   -0.0000


A =

  Columns 1 through 21

     1    -1     1     1    -1    -1     1     1     1    -1    -1     1     1    -1    -1    -1    -1    -1     1    -1     1

  Columns 22 through 25

    -1     1    -1    -1

[Walter Roberson]

0 and -0 display as 0 not as 0.0000 or -0.0000. So your values are not 0 and -0

Give the command

 format long g

and then display your values again

Answer 2

[Walter Roberson]

See sum sign

However, your description does not match your example. You say you want to replace positive numbers with 1, but your example shows replacing the only positive number with 0.

[Haya Ali]

My mistake.