This question already has answers here:
How do I calculate a logarithm in iOS? [duplicate]
(3 answers)
Closed 9 years ago.
I need to calculate Log (base 10) and Log (base e – Naperian/Natural).
I am now assuming that Log (base 10) is:
double log10 ( double );
And am I correct to assume that Log (base e – Naperian/Natural) is just:
double log ( double );
Thanks
Check man 3 log for man page. In iOS 6 there is also vecLib which has logarithmic functions.
Related
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C++ SSE Intrinsics: Storing results in variables [closed]
(1 answer)
print a __m128i variable
(4 answers)
SSE: Difference between _mm_load/store vs. using direct pointer access
(3 answers)
How to extract bytes from an SSE2 __m128i structure?
(1 answer)
Is `reinterpret_cast`ing between hardware SIMD vector pointer and the corresponding type an undefined behavior?
(2 answers)
Closed 1 year ago.
I can use _mm_set_epi64 to store two uint64_ts into a __m128 intrinsic. But hunting around, I see various ways to get the values back out: There's reinterpret_cast (and it's evil twin C-style casts), it's sibling union { __m128; uint64[2]; }; and memcpy, there's accessing fields of __m128. There's __m128i _mm_load_si128(__m128i *p);, but I'm not seeing a _mm_get_* function. Am I missing something? If there's a _mm_set_epi64 then there must be a non-cast way to get the uint64_ts back out, right? (Otherwise why would they bother providing _mm_set_epi64?)
I see Get member of __m128 by index? but the "correct answer" has a broken link and implies there's a load function, but all the loads I see map __m128 to __m128. Shouldn't there be a void _mm_get_epi64(__m128, uint64_t* outbuf)?
This question already has answers here:
Is floating point math broken?
(31 answers)
Closed 2 years ago.
Can someone explain to me why the following sum gives wrong result in dart?
final double result = 90071992547409.9 + 0.01;
print(result);
It prints the number 90071992547409.92
According to Dart documentation:
Dart doubles are 64-bit floating-point numbers as specified in the IEEE 754 standard.
It's because of floating-point arithmetic. In your case (I used this converter):
90071992547409.9 = 90071992547409.90625 ~= 90071992547409.91
0.01 = 0.01000000000000000020816681711721685132943093776702880859375 ~= 0.01
90071992547409.91 + 0.01 = 90071992547409.92
The best solution in dart is to use the decimal package.
This question already has answers here:
How to convert a double to an int in Dart?
(11 answers)
How do you round a double in Dart to a given degree of precision AFTER the decimal point?
(28 answers)
Closed 3 years ago.
I want to round a double.
Double x = 5.56753;
x.toStringAsFixed(2);
When i put this, it gives 5.57000.
But i want to get 5.57. How do i get it?
there is num class contained function round():
Num
double numberToRound = 5.56753;
print(numberToRound.round());
//prints 6
If you want decimals
double n = num.parse(numberToRound.toStringAsFixed(2));
print(n);
//prints 5.57
check comment sujestion
For rounding doubles checkout: https://api.dartlang.org/stable/2.4.0/dart-core/double/round.html
Rounding won't work in your case because docs says:
Returns the integer closest to this.
So it will give 6 instead 5.57.
Your solution:
double x = 5.56753;
String roundedX = x.toStringAsFixed(2);
print(roundedX);
This question already has answers here:
How to properly format currency on ios
(8 answers)
How to input currency format on a text field (from right to left) using Swift?
(9 answers)
Closed 4 years ago.
I have a values like that: 100, 1220, 10015 basically last 2 digits are cents and I need to convert to dollar (currency) format similar to:
1.00, 12.20, 100.15
Can somebody suggest a quick implementation?
var a = 1011
var b = Double(a) / 100
This question already has answers here:
A way to round Floats down
(11 answers)
Closed 6 years ago.
I have number num = 24.89808 and want to round it to 24.89
How can i do it?
i tried num.round(2) but it gives me 24.9 also number_to_currency=>24.90
If you are talking about rounding, 24.9 is by all means the correct result. Whether you are interested in ceiling it, here you go:
(24.89808 * 100).floor / 100.0
#⇒ "24.89"
First convert that into a decimal and then round it two two places,
Try this command,
num.to_d.round(2, :truncate).to_f
2.2.4 :040 > num = 24.89808
=> 24.89808
2.2.4 :041 > num.to_d.round(2,:truncate).to_f
=> 24.89