I like to create an Argand Diagram from a set of complex number by using Objective-C.
Are there any solution or template that are available that can help me to do this?
Can anyone recommend an approach?
Similar youtube link is provided but it's an android program: https://www.youtube.com/watch?v=s0oTeZ12_ig
- (void)ComputeABCD
{
double designFrequency = 1e9;
double simulateFrequency = 1.5e9;
double pi = 3.14159265359;
double omega = 2*pi*simulateFrequency;
double thetarad=1;
complex double cascadedA=1+0*I;
complex double cascadedB=0+0*I;
complex double cascadedC=0+0*I;
complex double cascadedD=1+0*I;
complex double A=0+0*I;
complex double B=0+0*I;
complex double C=0+0*I;
complex double D=0+0*I;
complex double newA=0+0*I;
complex double newB=0+0*I;
complex double newC=0+0*I;
complex double newD=0+0*I;
int index=0;
for (id element in storeImpedance)
{
id element2 = [storeLength objectAtIndex:index];
id element3 = [storeIndex objectAtIndex:index];
NSNumber *numberImpedance = (NSNumber *)element;
double valueImpedance = [numberImpedance doubleValue];
NSNumber *numberLength = (NSNumber *)element2;
double valueLength = [numberLength doubleValue];
NSNumber *numberIndex = (NSNumber *)element3;
NSInteger valueIndex = [numberIndex integerValue];
++index;
if (valueIndex==0)
{
thetarad=valueLength*pi/180*simulateFrequency/designFrequency;
A=cos(thetarad);
B=I*valueImpedance*sin(thetarad);
C=I*sin(thetarad)/valueImpedance;
D=cos(thetarad);
}
if (valueIndex==1)
{
thetarad=valueLength*pi/180*simulateFrequency/designFrequency;
A=1;
B=0;
C=(I*tan(thetarad))/valueImpedance;
D=1;
}
newA=cascadedA*A+cascadedB*C;
newB=cascadedA*B+cascadedB*D;
newC=cascadedC*A+cascadedD*C;
newD=cascadedC*B+cascadedD*D;
cascadedA=newA;
cascadedB=newB;
cascadedC=newC;
cascadedD=newD;
}
printf("The MAT ABCD is:\n");
printf("%g + %gi\n", creal(cascadedA), cimag(cascadedA));
printf("%g + %gi\n", creal(cascadedB), cimag(cascadedB));
printf("%g + %gi\n", creal(cascadedC), cimag(cascadedC));
printf("%g + %gi\n", creal(cascadedD), cimag(cascadedD));
}
Related
I am trying to get one digit after decimal and store it as double.
For eg : -
float A = 146.908295;
NSString * string = [NSString stringWithFormat:#"%0.01f",A]; // op 146.9
double B = [string doubleValue]; // op 146.900000
i want output as 146.9 in double or float form..,before duplicating or downvoting make sure the answer to this output is given..
Thanks
Edited:-
NSString * str = [NSString stringWithFormat:#"%0.01f",currentAngle];
tempCurrentAngle = [str doubleValue];;
tempCurrentAngle = tempCurrentAngle - 135.0;
if (tempCurrentAngle == 8.7) {
NSLog(#"DONE ");
}
here currentAngle is coming from continueTrackingWithTouch method, which will be in float..here it does not enter in if loop even when tempCurrentAngle value changes to 8.700000 .
You can compare string values instead of double like,
double currentAngle = 143.7; // I have taken static values for demo.
double tempCurrentAngle = 0.0;
NSString * str = [NSString stringWithFormat:#"%0.01f",currentAngle];
tempCurrentAngle = [str doubleValue];;
tempCurrentAngle = tempCurrentAngle - 135.0;
NSString *strToCompare = [NSString stringWithFormat:#"%0.01f",tempCurrentAngle];
if ([strToCompare isEqualToString:#"8.7"] ) {
NSLog(#"DONE ");
}
If you debug once line by line then you will get idea that why it was not entering in if caluse.
tempCurrentAngle get 143.69999999999999 when you convert str to double then you reduce 135.0 from it so it's value will be 8.6999999999999886 and then you compare it with 8.7 then it will definitely not being equal! but if you convert tempCurrentAngle string with one decimal point then it will be 8.7! so you should compare string values instead of double!
I am making a game that requires me to use very large numbers. I believe I am able to store very large numbers with NSDecimal. However, when displaying the numbers to users I would like to be able to convert the large number to a succinct string that uses characters to signify the value eg. 100,000 -> 100k 1,000,000 -> 1.00M 4,200,000,000 -> 4.20B and so forth going up to extremely large numbers. Is there any built in method for doing so or would I have to use a bunch of
NSDecimalCompare statements to determine the size of the number and convert?
I am hoping to use objective c for the application.
I know that I can use NSString *string = NSDecimalString(&NSDecimal, _usLocale); to convert to a string could I then do some type of comparison on this string to get the result I'm looking for?
Use this method to convert your number into a smaller format just as you need:
-(NSString*) suffixNumber:(NSNumber*)number
{
if (!number)
return #"";
long long num = [number longLongValue];
int s = ( (num < 0) ? -1 : (num > 0) ? 1 : 0 );
NSString* sign = (s == -1 ? #"-" : #"" );
num = llabs(num);
if (num < 1000)
return [NSString stringWithFormat:#"%#%lld",sign,num];
int exp = (int) (log(num) / 3.f); //log(1000));
NSArray* units = #[#"K",#"M",#"G",#"T",#"P",#"E"];
return [NSString stringWithFormat:#"%#%.1f%#",sign, (num / pow(1000, exp)), [units objectAtIndex:(exp-1)]];
}
Some sample examples:
NSLog(#"%#",[self suffixNumber:#99999]); // 100.0K
NSLog(#"%#",[self suffixNumber:#5109999]); // 5.1M
Source
Solved my issue: Can only be used if you know that your NSDecimal that you are trying to format will only be a whole number without decimals so make sure you round when doing any math on the NSDecimals.
-(NSString *)returnFormattedString:(NSDecimal)nsDecimalToFormat{
NSMutableArray *formatArray = [NSMutableArray arrayWithObjects:#"%.2f",#"%.1f",#"%.0f",nil];
NSMutableArray *suffixes = [NSMutableArray arrayWithObjects:#"k",#"M",#"B",#"T",#"Qa",#"Qi",#"Sx",#"Sp",#"Oc",#"No",#"De",#"Ud",#"Dud",#"Tde",#"Qde",#"Qid",#"Sxd",#"Spd",#"Ocd",#"Nvd",#"Vi",#"Uvi",#"Dvi",#"Tvi", nil];
int dick = [suffixes count];
NSLog(#"count %i",dick);
NSString *string = NSDecimalString(&nsDecimalToFormat, _usLocale);
NSString *formatedString;
NSUInteger characterCount = [string length];
if (characterCount > 3) {
NSString *trimmedString=[string substringToIndex:3];
float a;
a = 100.00/(pow(10, (characterCount - 4)%3));
int remainder = (characterCount-4)%3;
int suffixIndex = (characterCount + 3 - 1)/3 - 2;
NSLog(#"%i",suffixIndex);
if(suffixIndex < [suffixes count]){
NSString *formatSpecifier = [formatArray[remainder] stringByAppendingString:suffixes[suffixIndex]];
formatedString= [NSString stringWithFormat:formatSpecifier, [trimmedString floatValue] / a];
}
else {
formatedString = #"too Big";
}
}
else{
formatedString = string;
}
return formatedString;
}
How would I get the nearest float in my array to a float of my choice? Here is my array:
[1.20, 1.50, 1.75, 1.95, 2.10]
For example, if my float was 1.60, I would like to produce the float 1.50.
Any ideas? Thanks in advance!
You can do it by sorting the array and finding the nearest one.
For this you can use sortDescriptors and then your algorithm will go.
Even you can loop through, by assuming first as the required value and store the minimum absolute (abs()) difference, if next difference is lesser than hold that value.
The working sample, however you need to handle other conditions like two similar values or your value is just between two value like 2 lies between 1 and 3.
NSArray *array = #[#1.20, #1.50, #1.75, #1.95, #2.10];
double my = 1.7;
NSNumber *nearest = array[0];
double diff = fabs(my - [array[0] doubleValue]);
for (NSNumber *num in array) {
double d = [num doubleValue];
if (diff > fabs(my - d) ) {
nearest = num;
diff = my - d;
}
}
NSLog(#"%#", nearest);
I have to count how many decimal digits are there in a double in Xcode 5. I know that I must convert my double in a NSString, but can you explain me how could I exactly do? Thanks
A significant problem is that a double has a fractional part which has no defined length. If you know you want, say, 3 fractional digits, you could do:
[[NSString stringWithFormat:#"%1.3f", theDoubleNumber] length]
There are more elegant ways, using modulo arithmetic or logarithms, but how elegant do you want to be?
A good method could be to take your double value and, for each iteration, increment a counter, multiply your value by ten, and constantly check if the left decimal part is really near from zero.
This could be a solution (referring to a previous code made by Graham Perks):
int countDigits(double num) {
int rv = 0;
const double insignificantDigit = 8;
double intpart, fracpart;
fracpart = modf(num, &intpart);
while ((fabs(fracpart) > 0.000000001f) && (rv < insignificantDigit))
{
num *= 10;
fracpart = modf(num, &intpart);
rv++;
}
return rv;
}
You could wrap the double in an instance of NSNumber and get an NSString representation from the NSNumber instance. From there, calculating the number of digits after the decimal could be done.
One possible way would be to implement a method that takes a double as an argument and returns an integer that represents the number of decimal places -
- (NSUInteger)decimalPlacesForDouble:(double)number {
// wrap double value in an instance of NSNumber
NSNumber *num = [NSNumber numberWithDouble:number];
// next make it a string
NSString *resultString = [num stringValue];
NSLog(#"result string is %#",resultString);
// scan to find how many chars we're not interested in
NSScanner *theScanner = [NSScanner scannerWithString:resultString];
NSString *decimalPoint = #".";
NSString *unwanted = nil;
[theScanner scanUpToString:decimalPoint intoString:&unwanted];
NSLog(#"unwanted is %#", unwanted);
// the number of decimals will be string length - unwanted length - 1
NSUInteger numDecimalPlaces = (([resultString length] - [unwanted length]) > 0) ? [resultString length] - [unwanted length] - 1 : 0;
return numDecimalPlaces;
}
Test the method with some code like this -
// test by changing double value here...
double testDouble = 1876.9999999999;
NSLog(#"number of decimals is %lu", (unsigned long)[self decimalPlacesForDouble:testDouble]);
results -
result string is 1876.9999999999
unwanted is 1876
number of decimals is 10
Depending on the value of the double, NSNumber may do some 'rounding trickery' so this method may or may not suit your requirements. It should be tested first with an approximate range of values that your implementation expects to determine if this approach is appropriate.
#"{0, 1.0, 0, 1.0}"
I wish to convert the above string to a struct like this:
struct MyVector4 {
CGFloat one;
CGFloat two;
CGFloat three;
CGFloat four;
};
typedef struct MyVector4 MyVector4;
CGRectFromString() does the same thing, only for CGRect. How can I do it for my own structs?
If there is a function for rect it means that it is not working by default.
You have to create your own function something like MyVector4FromString.
You may like to to know that you can init struct object like this also.
MyVector4 v1 = {1.1, 2.2, 3.3, 4.4};
This is a very easy C syntax. so I don't think you require to init from string.
See here : 4.7 — Structs
But if you are getting string from server or from other function than yes you have to create your function to do this. You can parse string and init 4 float value.
This link will help you to divide string in multiple part : Split a String into an Array
All the best.
It can be done in the following way:
-(MyVector4)myVector4FromString:(NSString*)string
{
NSString *str = nil;
str = [string substringWithRange:NSMakeRange(1, string.length - 1)];
NSArray *strs = [str componentsSeparatedByString:#","];
MyVector4 myVec4 = {0,0,0,0};
for (int i=0; i<4; i++)
{
CGFloat value = ((NSString*)[strs objectAtIndex:i]).floatValue;
if (i==0) { myVec4.one = value; } else
if (i==1) { myVec4.two = value; } else
if (i==2) { myVec4.three = value; } else
if (i==3) { myVec4.four = value; }
}
return myVec4;
}
This function can parse strings in format shown in your question like #"{12.0,24.034,0.98,100}"