sigmoid function value for parameter a and b

Please can someone help me with sigmoid function. Please can anyone tell me what values i should give for a and b so that i get for

 y0=sigmf(0,[a b]) % y0 value less than 0.5

and for

 y1=sigmf(1,[a b]) % y1 value greater than 0.5

Answer 1

[Jan]

According to my calculations you have to pick 0<b<1 and a>0.

E.g. b=1/2 and a=1

[Jan]

Laurent was obviously a bit faster than me doing the math, but it's nice to have a result double checked :)

[Elysi Cochin]

thank you all

Answer 2

[Laurent]

Well, if the only requirement is that y0 < 0.5 for x=0 and y1 > 0.5 for x=1, then for 0 < b < 1 and a > 0 it should work.

[Elysi Cochin]

sir for x = 0, it should be a value less than 0.5 and for x = 1, it should be a value greater than 0.5

such a value i need for a and b