10 Band Equaliser using NOVOCAINE - ios

Im trying to build a 10 band Equaliser using NOVOCAINE.
I copied the Equaliser.mm's code in viewWillAppear, and added 9 more Sliders in the xib file, and changed IBAction code too this :
-(void)HPFSliderChanged:(UISlider *)sender {
PEQ[sender.tag - 1].centerFrequency = sender.value;
NSLog(#"%f",sender.value);
}
What I want to know is if I am doing this the right way or not ? and the what will be range of the Sliders ? Like in HPF example, the slider range is 2k to 8k. Need some guidance here.
Thanks.

EDIT: after your comment, I think it is clearer what you are asking.
Take the code to instantiate a NVPeakingEQFilter:
NVPeakingEQFilter* PEQ = [[NVPeakingEQFilter alloc] initWithSamplingRate:self.samplingRate];
PEQ.Q = QFactor;
PEQ.G = gain;
PEQ.centerFrequency = centerFrequencies;
you need define 3 parameters: Q, G, and centerFrequency. Both Q and centerFrequency are usually fixed (QFactor in my case is a constant equal to 2.0).
So, you have 10 sliders: each one corresponds to a fixed centerFrequency. I suggested iTunes values: 32Hz, 64Hz, 125Hz, 250Hz, 500Hz, 1KHz, 2KHz, 4KHz, 8KHz, 16KHz. You do not want to change those values when the slider value changes.
What you want to change when the slider value changes is the gain (G). At init time, G can be set to 0.0. This means "no amplification/attenuation".
When the slider moves, you change G, so actually you would do:
PEQ[sender.tag - 1].G = sender.value * kNominalGainRange;
where kNominalGainRange is 12.0, so if sender.value goes from -1.0 to +1.0, G goes from -12 to +12.
Hope this helps.
What I want to know is if I am doing this the right way or not ?
you do not show much code, but HPFSliderChanged seems correct. If you have any specific issue you should describe it and post more code.
and the what will be range of the Sliders ?
Actually, there is no rigid rule when it come to equalisers. iTunes goes from -12db to +12db, but you could use different ranges (with the only caveat being distortion).
Like in HPF example, the slider range is 2k to 8k. Need some guidance here.
again, you can take iTunes equaliser as an example (32Hz, 64Hz, 125Hz, 250Hz, 500Hz, 1KHz, 2KHz, 4KHz, 8KHz, 16KHz), or you can google for images of real equalisers and see which bands they use.

Related

How do I create a calculator that with one input populates several label fields with different values?

I am new to using Xcode, slowly learning as I go. Attempting to create a calculator where I input a weight which will cause multiple different labels to display different values.
StoryBoard
This is how I have the storyboard setup. Basically behind the scenes I need the values calculated for each item. For example, I want to take the user input ("weight in kilograms" x 80) / 24 and have the result show up on the label to the right of "Fluid Rate". At the same time I will need to have a different calculation for each label.
Here is my code so far.
ViewController
One of the big issues I'm running into so far is that even when I set a value like, let fluid = 80, when I try to setup a calculation with it, Xcode tells me I cannot use a textfield with integers or binary operators. How do I go about making Xcode recognize the user input from the textfield as an integer?
I go through the problem you are facing I am giving the sample code snippet which might be helpful to you.
var fluidRate = 0
var GIR = 0
var enteredValue = 10
{
didSet {
fluidRate = enteredValue * 10 //consider your formula calculations
GIR = enteredValue * 50 //consider your formula calculations
//you can do like that
//self.fluidlabel.text = "\(fluidRate)"
}
}
enteredValue = 30
GIR
fluidRate
How do I go about making Xcode recognize the user input from the textfield as an integer?
Read the section Converting Strings in the documentation for Int.
That will get you from text to integer and it looks like you already know how to go the other way
HTH

Lua script for iOS getColors within range?

I am trying to capture the pixel color of a specific letter in a font within an iOS app. I'd then use that color in an if/then statement to determine the next action of my script. I'm finding no easy way to determine if the color/colors I'm finding are the right ones. Here's my current process: I start recording my inputs and continuously click around the letter. I end up with something like touchdown(123,456). I change that to alert(getColor(123,456)) and run, which produces a popup that tells me the color such as 3094841 (not sure why the colors are in numeric format, but they are). I do this for each touchdown line that is captured. The problem is, I don't know an easy way to determine which color is the small letter I'm trying to tap.
Is there a lua function that will capture and display a range of colors between 2 points? If there were, I could see the commonality of all of the colors within the 2 points and make at least an educated guess as to which is the color in the font. Or even more useful - is there a tool I can use to type in the color I'm getting back and have it display the corresponding color, so I can compare them. That'd be the easiest. Hope this makes sense. Any help would be awesome. In case it matters, I'm using Autotouch 8 on an iPhone 5.
TIA
I use this function often in my games.
I find the easiest way to get a color you want to execute every single time is to take a snap of the screen you're checking and then use the helper on getColor(x, y)
And you can use this to alert your color.
local color = getColor(x, y)
alert(color)
-- You can also use:
log(color)--this one keeps it in your log in case you can write it down immediately.
To use this in an if/then statement
function = namedfunction()
local color = getColor(x, y)
if color == YOURCOLOR then
else
end
end
namedfunction();
Note that I have the iPhone 5 iOS 8.3 and I have the most recent AutoTouch from Cydia. If you don't have the helper when you're scripting it might be worth it to check if Cydia offers a capatable version.
Edit: I am running version 3.5.3-8 of Autotouch.

How to move image with low values?

The problem is simple: I want to move (and later, be able to rotate) an image. For example, every time i press the right arrow on my keyboard, i want the image to move 0.12 pixels to the right, and every time i press the left arrow key, i want the image to move 0.12 pixels to the left.
Now, I have multiple solutions for this:
1) simply add the incremental value, i.e.:
image.x += 0.12;
this is of course assuming that we're going to the right.
2) i multiplicate the value of a single increment by the times i already went into this particular direction + 1, like this:
var result:Number = 0.12 * (numberOfTimesWentRight+1);
image.x = result;
Both of these approaches work but produce similiar, yet subtly different, results. If we add some kind of button component that simply resets the x and y coordinates of the image, you will see that with the first approach the numbers don't add up correctly.
it goes from .12, .24, .359999, .475 etc.
But with the second approach it works well. (It's pretty obvious as to why though, it seems like += operations with Numbers are not really precise).
Why not use the second approach then? Well, i want to rotate the image as well. This will work for the first attempt, but after that the image will jump around. Why? In the second approach we never took the original position of the image in account. So if the origin-point shifts a bit down or up because you rotated your image, and THEN you try to move the image again: it will move to the same position as if you hadn't rotated before.
Alright, to make this short:
How can i reliably move, scale and rotate images for 1/10 of a pixel?
Short answer: I don't know! You're fighting with floating point math!
Luckily, I have a workaround, if you don't mind.
You store the location (x and y) of the image in a separate variable... at a larger scale. Such as 100x. So 123.45 becomes 12345, and you then divide by 100 to set the attribute that flash uses to display.
Yes, there are limits to number sizes too, but if you're willing to accept some error rate, and the fact that you'll be limited to, I dunno, a million pixels in each direction, you can fit it in a regular int. The only rounding error you will encounter will be a single rounding error when you divide by 100 (or the factor you used). So instead of the compound rounding error which you described (0.12 * 4 = 0.475), you should see things like 0.47999999. Which doesn't matter because it's, well, so small.
To expand on #Pimgd answer a bit, you're probably hitting a floating point error (multiple +='s will exaggerate the error more than one *='s) - Numbers in Flash are 53-bit precision.
There's also another thing to keep in mind, which is probably playing a bigger role with such small movement values; Flash positions all objects using twips, which is roughly about 1/20th of a pixel, or 0.05, so all values are rounded to this. When you say image.x += 0.12, it's actually the equivalent of image.x += 0.10, hence which the different becomes apparent; you're losing 0.02 of a pixel with every move.
You should be able to get around it by moving to another scale, as #Pimgd says, or just storing your position separately - i.e. work from a property _x rather than image.x so you're not losing that precision everytime:
this._x += 0.12;
image.x = this._x;

need help calculating in xcode

I will explain my project before I get into my question. On the first view you select either UK shoe size (button) or US shoesize (button). then it brings you to another view which has 2 text boxes.(labeled women or mens) If you select men and type a "9" then in the background it does this equation (21.75 + shoeSize) / 3= ans.
It will then take the answer and do this answer / 12 = Feet. Then one the next screen it will have a label that says "how many feet?" then you enter how many feet. In the background it will do this feet * whateverYouPutInBox = steps. Then display the answer on a new screen. I need to know how to do the background equations! (I'm new to iOS programming) this may seem simple to most people. But please help me. If you need anything explained please reply!
Just reverse your equations:
float answer = (21.75 + [shoeSizeTextfield.text floatValue])/3;
float feet = answer/12;
float steps = feet * [numberOfFeetTextField.text floatValue];
And no need to run them in the background since they take a fraction of a second.
But when you say "display on a new screen" what do you mean? You want to transfer the values to another view controller? If so, check out this answer: Passing Data between View Controllers.

How to draw an effect (Gloss with metallic lustre) on concentric circle such as following?

I referred to following article. What I actually need to draw is concentric/ Concrete circles with an effect as shown in image below.
I am finding it difficult to a) Draw the white streaks radially b) Find some key terms to search for related articles to proceed further on this.
Any hint or link to read about this will be of great help.
Try these
Metallic Knob
Metallic Knob 2
http://maniacdev.com/2012/06/ios-source-code-example-making-reflective-metallic-buttons-like-the-music-app
This is a tutorial on making reflective metal buttons. You can apply the techniques from the source code to whatever object you're trying to make. The source code is found here on github. I just googled "ios objective c metal effect" because that's what you're trying to do, right? The metal effect appears in concentric circles and changes as you tilt your phone, just as the iOS6 music slider does.
I don't have any code for you but the idea is actually quite simple. You're drawing a number of lines radiating from a single, central point (say 50,50) to four different sets of points. First set is for x = 0 to 100, y = 0. Second set is for y = 0 to 100, x = 0. Third set is for x = 0 to 100, y = 100. Fourth set is for y = 0 to 100, x = 100. And for each step you need to either change the colour from white to black or white to grey in increments or use a look up table with your colour values in it.

Resources