convert float string to string

allcc

I'm communicating with a microcontroller using the serial port using a demo I found and it works great. The issue is I do not want a floating point number to go to the microcontroller. Right now it does, using the code below.

What I would like to do is drop the decimal (or round off) "subtext[counter]" before sending via myPort.write. I have tried converting it to an int, but then myport.write doesn't like it. If there is a way to send an INT via myPort.write that would also be a good solution.

if(counter<subtext.length){

pan = Float.valueOf(subtext[counter]);

pan = (pan + 0.01) * 11.2;

(subtext[counter]) = Float.toString(pan);

myPort.write(subtext[counter]);

GoToLoop

https://Processing.org/reference/nf_.html

allcc

nf expects ints, any way to do this with a string?

GoToLoop

Can't you just use your float pan variable w/ nf()?

quark

Use the round function to round the float to the nearest integer.

allcc

Yeah I've tried nf() and round. I'm using a serial monitor and I still see a decimal being transmitted.

I think I can work around this if I could send an int vs string via serial.

Is there a way to use myPort.write to send an int?

quark

How about

(subtext[counter]) = Integer.toString(round(pan));

allcc

Thanks. That helped, the output lost the decimal. But, now it's not doing the other math I have in there. Can you check this for me?

float pan = Integer.parseInt(subtext[counter]);

pan = (pan + 0.01) * 11.2;

(subtext[counter]) = Integer.toString(round(pan));

myPort.write(subtext[counter]);

What's the code markdown here anyway?

Thanks again.

jeremydouglass

From the nf() reference:

nf() is used to add zeros to the left and/or right of a number. This is typically for aligning a list of numbers. To remove digits from a floating-point number, use the int(), ceil(), floor(), or round() functions.

If you only want to remove some of the floating point digits then it gets a bit more complex. But in your case, you want just an int.

The question is whether you want low/low results:

5.1 = 5
5.9 = 5

or low/high results:

5.1 = 5
5.9 = 6

• low/low results: use int(), (int), or floor()
• low/high results: use round()

You can also use str() to convert any result to string.

Examples:

/**
 * Round Float to Int
 * 2016-10-24 Processing 3.2.1
 * https:// forum.processing.org/two/discussion/18679/convert-float-string-to-string
 **/

float f5_1 = 5.123;
float f5_9 = 5.987;

// round() function
println ( f5_1, "round()", round(f5_1) ); // 5.1 = 5
println ( f5_9, "round()", round(f5_9) ); // 5.9 = 6

// int() function
println ( f5_1, "int()  ", int(f5_1) );   // 5.1 = 5
println ( f5_9, "int()  ", int(f5_9) );   // 5.9 = 5

// (int) cast
println ( f5_1, "(int)  ", (int)f5_1 );   // 5.1 = 5
println ( f5_9, "(int)  ", (int)f5_9 );   // 5.9 = 5

// floor() function
println ( f5_9, "floor()", floor(f5_1) ); // 5.1 = 5
println ( f5_9, "floor()", floor(f5_9) ); // 5.9 = 5

// ceil() function
println ( f5_1, "ceil() ", ceil(f5_1) );  // 5.1 = 6
println ( f5_9, "ceil() ", ceil(f5_9) );  // 5.9 = 6

// ...convert rounded float to string
println ( f5_9, "str(round())", str(round(f5_9)) ); // 5.9 = "6"

Output:

5.123 round() 5
5.987 round() 6
5.123 int()   5
5.987 int()   5
5.123 (int)   5
5.987 (int)   5
5.987 floor() 5
5.987 floor() 5
5.123 ceil()  6
5.987 ceil()  6
5.987 str(round()) 6

quark

But, now it's not doing the other math

Line 2 will take the value in pan add 0.01 and multiply by 11.2 and then store the result in pan overwritng the previous value.

Line 3 rounds the value to the nearest integer and converts it to a String leaving pan unchanged

What other math???

Can you check this for me?

No I don't use the serial library perhaps someone else can help you.

Code markdown read the sticky post Format Text and Code

allcc

Thanks for all the help guys. We're up and running.