OpenEuphoria

Re: Phix:Converting Decimal Value to String Hurts

• Posted by euphoric (admin) Jun 25, 2020
• 938 views

So, I played around with it and got these results:

function precise_to_string(atom number, integer prec) 
    atom i = number * power(10,prec) 
    integer decpos = match(".",sprint(number)) 
    string number_str = sprintf("%d",i) 
    number_str = number_str[1..decpos-1] & "." & number_str[decpos..$] 
    return number_str 
end function 
 
for t=10 to 20 do 
    ?precise_to_string(23.7,t) 
end for 
 
for t=10 to 20 do 
    ?precise_to_string(1234567890.1234567890,t) 
end for 
 
for t=10 to 20 do 
    ?precise_to_string(23.123456789012345678901,t) 
end for 

"23.7000000000" 
"23.70000000000" 
"23.700000000000" 
"23.7000000000000" 
"23.70000000000000" 
"23.700000000000000" 
"23.7000000000000000" 
"23.70000000000000000" 
"23.700000000000000000" 
"23.7000000000000000000" 
"23.70000000000000000000" 
"1234567890.1234568088" 
"1234567890.12345680884" 
"1234567890.123457064684" 
"1234567890.1234570646840" 
"1234567890.12345706468402" 
"1234567890.123457064684088" 
"1234567890.1234564820008622" 
"1234567890.12345706468408804" 
"1234567890.123457064684088044" 
"1234567890.1234570646840880466" 
"1234567890.12345706468408804666" 
"23.1234567890" 
"23.12345678901" 
"23.123456789012" 
"23.1234567890123" 
"23.12345678901234" 
"23.123456789012344" 
"23.1234567890123446" 
"23.12345678901234468" 
"23.123456789012344682" 
"23.1234567890123446822" 
"23.12345678901234446642" 

Phix precision is 16 digits, I guess.

What I learned with this experiment is that the number of digits to the left of the decimal matters!

16 digits TOTAL, not 16 digits to the right of the decimal!

Who knew?