Strings and datatypes problem...

Programming Questions

Jesse Sco..

Strings and datatypes problem...

in Programming Questions • 2 years ago

Hi. I'm using the v3ga blob detection library, and im interested in trying to get at the x/y coordinates of the edge vertex and save them to a file...

but im getting a "cannot convert from float to int" error on my string array code (line 5 here)...

I'm not really sure about trying to set or convert the datatype, or even which part of the line it's referring to?

I know that eA.x is a float, as per v3ga's documentation, so Im assuming that "lines" is being read as an integer array ? But im not sure how that is, if I did that, or how to change it...

eA = b.getEdgeVertexA(m);
eB = b.getEdgeVertexB(m);
if (eA !=null && eB !=null) {
vertex(eA.x*cam.width, eA.y*cam.height);
String[] lines = new String[eA.x];
}

I haven't really had cause to play with strings and arrays very often in Processing, and only vaguely understand them... so im a bit lost... any help/leads appreciated.

thanks in advance,

~ J

Replies(8)

cedrickie..

Re: Strings and datatypes problem...

2 years ago

the problem is, you are creating an string array with the length eA.x.

how do you want the file to be formated?

Jesse Sco..

Re: Strings and datatypes problem...

2 years ago

you again!

right, my bad... I forgot that the 2nd argument was the length... that makes sense.

ok, then I can change it to 'm' (see code), I don't get the error...

for (int m=0;m<b.getEdgeNb();m++) {
eA = b.getEdgeVertexA(m);
eB = b.getEdgeVertexB(m);
if (eA !=null && eB !=null) {
vertex(eA.x*cam.width, eA.y*cam.height);
String[] lines = new String[m];
if (export == true) {
saveStrings("GCode.txt", lines);
}
}
}

but I am then unsure as how to get eA.x and eA.y into the array...

I am aiming to create a file that writes the x/y position, with some added formatting...

eg. G1 X52.4784 Y20.1779

cedrickie..

Re: Strings and datatypes problem...

2 years ago

still, now you create the array with the length m again and again for every edge...

but its a bit complicated if you want to put everything in a string array as you need to know the number of blobs and their edges to create the array.its not necessary though.

why not using just printwriter...
http://processing.org/reference/PrintWriter.html

Jesse Sco..

Re: Strings and datatypes problem...

2 years ago

yes, i know, i wasn't sure about how to get at the floats if i didn't make my array inside to for loop, and i kind of want to make separate arrays for each edge/shape anyways...

i can get the number of blobs - that's part of the larger code already...

i didn't know about PrintWriter... I can give that a shot, but I wanted to addend text to make it into a proper GCode file...

ie. something like ("G1", "X"+eA.x, " ", "Y"+eA.y) ...

cedrickie..

Re: Strings and datatypes problem...

2 years ago

that shouldnt be a problem, you can add anything you want into the output.println() function.
as you already almost did. could look like

output.println("G1"+"X"+eA.x+" Y"+eA.y);

i guess G1 is a counting up, right? so you have to create some kind of variable here that counts

Jesse Sco..

Re: Strings and datatypes problem...

2 years ago

Yeah, I just figured that out, once I took a closer look.

G1 isn't a variable, it's a GCode header...

getting there... thanks for your help.

PhiLho

Re: Strings and datatypes problem...

2 years ago

You are trying to create an array, ie. a number of Strings grouped together. But you are using a float number to define the number of entries: 2.2 entries doesn't make sense... And a length equals to a coordinate doesn't make sense either, in general.
But perhaps you were trying to convert the dimension to a String? In that case, you can just use the str() function.

Jesse Sco..

Re: Strings and datatypes problem...

2 years ago

Thanks again Cedric, PhiLo...

PrintWriter seems to be working fine, but because I am trying to access local variables, it is writing to the file for every count in my for loop...

the str() approach - if im doing it right - seems to return [0]null and [1]null ...

if (export == true) {

output.println("G1" + " " + "X" + eA.x*cam.width + " " + "Y" + eA.y*cam.height);

String[] xy = new String[2];

String x = str(eA.x);

String y = str(eA.y);

String joinedXY = join(xy, " ");

saveStrings("strings.txt", xy);

}

Maybe to clarify, to make sure im even on the right track, is to say that what I am looking for is a method to make a string out of the x+y position of each blob, and write that to a file just once (not iterate it through my for loop). I would also like to know when i move onto a new blob and write a different line before I move back to the x/y of the next blob...

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