Related to : Calculate y derivative of image

calculate edge strength of image 
mean will give you the mean value of your image. If you're using Canny
as above you can do:
Scalar pixelMean = mean(draw);
To get the mean of only the edge pixels, you would use the image as
the mask as well:
Scalar edgeMean = mean(draw, draw);
Unfortunately, since Canny sets all edge pixels to 255, your mean will
always be 255. If this is the measure you're looking for, you'll
probably want

How to implement a derivative of a symbolic function by a 'symfun' in Matlab? 
In newer versions of Matlab (I'm using R2014b) the error message is
clearer:
Error using sym/diff (line 26)
All arguments, except for the first one, must not be symbolic
functions.
So, it looks like sym/diff cannot take a derivative with respect to
what the documentation calls an abstract or arbitrary symfun, i.e.,
one without a definition. This limitation is not explicitly mentioned
in th

Change image on click, keep image and remove if other image is clicked 
var sourceSwap = function () {
var $this = $(this);
if (!$this.hasClass('active')) {
var newSource = $this.data('altsrc');
$this.data('altsrc', $this.attr('src'));
$this.attr('src', newSource);
}
}
var makeActive = function() {
var $this = $(this);
// bring the active back (if any) to the first state
if($('img.active').length) {
var

How to use the Computed Value to calculate another 
You have to repeat the expression
Select cost ,
(service_charge*(costDiscount)) as service_charge ,
(service_tax*(costDiscount+((service_charge*(costDiscount))*(costDiscount))))
as service_tax
From VENDOR_ITEMS WHERE vendor_items_id = 264

Need to calculate when adding coin 
You are adding strings rather than numbers. You'll need to convert
your strings into numbers to add them together, and you shouldn't
clear your results first.
For example:
private void fiveP_Click(object sender, EventArgs e)
{
// balance.Clear(); < You don't need this.
balance.Text = ((double)balance.Text + 0.05).ToString();
}
