1. chk_pow_args() (to Andy)
Andy,
Here a corrected version which accounts also for 0^b, b!=0. I forgot
this case. But some more checks of this functions are recommended!
Have a nice day, Rolf
-------------------------------------------------------------------
constant lim = log(3e+307) -- needed for chk_pow_args()
-------------------------------------------------------------------
function chk_pow_args(object a, object b)
-- ------------
if atom(a) and atom(b) then
if a > 0.0 then
if b*log(a) < lim then
return 1
end if
elsif a < 0 then
if integer(b) then
if b*log(-a) < lim then
return 1
end if
else
return 0
end if
elsif b != 0.0 then -- case a=0 !
return 1
end if
return 0
elsif length(a) = length(b) then
for i = 1 to length(a) do
if not chk_pow_args(a[i],b[i]) then
return 0
end if
end for
end if
return 0
end function
-------------------------------------------------------------------
procedure test(atom a, atom b)
-- ----
if chk_pow_args(a,b) then
printf(1,"%24.15g%24.15g%24.15g\n",{a,b, power(a,b)})
else
printf(1,"%24.15g%24.15g %s\n",{a,b,"power(a,b) failed!"})
-- puts(1,"power() failiour! Abort.\n")
end if
end procedure
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test( 0.0950052, -300.784)
test( 0.0950053, -300.784)
test(-0.0950053, -300.784)
test( 3.01 , -30.000)
test(-3.01 , -30.000)
test( 3.01 , -31.000)
test(-3.01 , -31.000)
test(-3.01 ,-9100.000)
test(-3.01 ,-1e+9 )
test(-3.01 ,-1e+10 )
test( 3.01 ,-1e+9 )
test( 3.01 ,-1e+10 )
test( 1.01e+300, 1.01 )
test( 1.01e+300, -1.01 )
sequence s, t
s = { 0.0950052, 0.0950052, -0.0950053}
t = { -300.784 , -300.784 , -300.784 }
? s ? t ? chk_pow_args(s,t)
s = { 0.0950052, 0.0950052, -0.0950052 , 1}
t = { -300.784 , -300.784 , -300.784 }
? s ? t ? chk_pow_args(s,t)
abort(0)
-------------------------------------------------------------------
