Why am I getting Javascript (form) or (this.form) errors?

On Sat, 24 Mar 2007 08:51:19 -0700, Don Lancaster Gave us:

Depends on what version of java you have, and what you are developing scripts under, and their co-compatibilities.

JavaScript 1.1 being developed with Adobe GoLive 5.0.

here this refers to the imProveX function and there is no form property for function. pass the argument to setAmplitude function and all should be fine.

function imProveX (form) { setAmplitude (form) ;

??????????????

Try:

function imProveX (form) { setAmplitude (form) ; }

MassivePr> Depends on what version of java you have,

One of you two has no idea what he is talking about. "JavaScript: The World's Most Misunderstood Programming Language" by Douglas Crockford http://66.102.9.104/search?q=cache:gPOJH3E6QSkJ:

Don Lancaster a écrit :

function imProveX(form) { setAmplitude( form ); } this.form is already here ------^ and was called in button

To avoid mistakes try to do not use variables named as elements

function imProveX ( something ) { setAmplitude( something ); } or function imProveX ( aForm ) { setAmplitude( aForm ); }

it would have to be : 'form.p1s' is null or not an object

MassiveProng said the following on 3/24/2007 12:05 PM:

The this above refers to the function and as such has no property named "form". If you want to pass it, simply pass the parameter form.

Has nothing to do with any of that.

I see MicroBrain is metastasizing. =:-O

Cheers! Rich

There is a JavaScript NG and the posters there are *extremely* helpful.

No, it references the global object.

The only way imProveX's this keyword can refer to the imProveX function is if the calling function had set it that way using call or apply methods, and it doesn't. imProvex is called as a method of window, effectively as window.imProvex(). Therefore its this keyword references the window (global) object.

for the global object (unless one has been created elsewhere).

That should do it.

-- Rob

Thanks for the info.

btw, randy said the same thing :)

Yup.. if you add the missing brace.

Inside this function, 'this.form' is undefined. I think you need to pass 'form' to setAmplitude.

Because its null (not defined in the calling function imProveX.

Many thanks to everyone. Using (form) rather than (this.form) did it.

Presently exploring how to get this code to converge faster. Preferably instantly. Any suggestions?

Latest working version is

"Classic Wrong" doesn't know the difference between "Java"" and "Javascript". :(

I see c.l.j isn't the only group with an idiot. Are you related to VK by chance? Genetics might explain it.

Find a way to make a crude guess that is not too far off and use binary search (but i assume you already knew that. If the crude guess is fairly close, maybe use Taylors series on (1+error)?

Don Lancaster said the following on 3/25/2007 12:21 AM:

If by converging you mean execution speed, I didn't play very much but I was getting pretty instant results from the button clicks. You could remove some of the eval calls (I think there were 88 of them) where a lot of them appear to simply be eval'ing a string to convert it to a number. You could also look into some of the functions where you are referencing document.formName.elementName.value repeatedly with multiple elements. By storing a reference to document.formName you could speed up the look up time. In the reportToForm function you have lines like this:

document.mainform.fh07.value = fixFloat (h07, numPoints) ;

If, at the beginning of reportToForm you had a statement like this:

theForm = document.mainform;

Then you could change your references to this:

theForm.fh07.value

Which would pick up some speed gains.

After that, there are some other things I noticed in functions like hiHarm it appears you are doing some calculations and then calling another function. Are the p## variables changing each time you are calling that function? If not, move them outside the function and you don't have to repeatedly calculate them.

Been there, done that.

The series polynomials are very high order.

No, the JavaScript execution speed is not the immediate goal. But thanks for the tips.

The present goal is to find a fully deterministic solution to magic sinewave angles in a single step, rather than needing as many as five repeat (but remarkably fast converging) iterations.

Using JavaScript exploration to find (or prove not) an underlying algorithm.

Until recently, there was no reason to even suspect a deterministic solution equal to Magic Sinewave angles and Newton's method existed at all. 14x14 equations of multiple angle trig polynomials to the 28th power would not appear to offer trivial solutions. Chebycheff notwithstanding.

At present, Newton's Method works so extremely well that it strongly suggests a determnistic solution can be found. Finding one greatly simplifies extension to other numbers of pulses per quadrant.

And is the "missing link" to a totally solid Magic Sinewave theory.

Speed can come later. Speed is not an issue when zeroing out a few dozen low harmonics. Eventually the system can zero THOUSANDS of harmonics leading to a stunningly efficient means of digital sinewave generation.

Calculation time currently goes up with the third or fourth power of the number of harmonics zeroed.

See