mask

I have a 2D numpy array A of (60,1000) dimensions. Say, I have a variable idx=array([3,72,403, 512, 698]) . Now, I want to mask all the elements in the columns specified in idx . The values in these columns might appear in other columns but they shouldn't be masked. Any help would be appriciated. In [22]: A = np.random.rand(5, 10) In [23]: idx = np.array([1, 3, 5]) In [24]: m = np.zeros_like(A) In [25]: m[:,idx] = 1 In [26]: Am = np.ma.masked_array(A, m) In [27]: Am Out[27]: masked_array(data = [[0.680447483547 -- 0.290757600047 -- 0.0718559525615 -- 0.334352145502 0.0861242618662 0

I have a pandas dataset that I want to downsize (remove all values under x). The mask is df[my_column] > 50 I would typically just use df = df[mask] , but want to avoid making a copy every time, particularly because it gets error prone when used in functions (as it only gets altered in the function scope). What is the best way to subset a dataset inplace? I was thinking of something along the lines of df.drop(df.loc[mask].index, inplace = True) Is there a better way to do this, or any situation where this won't work at all? You are missing the inplace parameter : df.drop(df[df.my_column < 50]

I am trying to use a CALayer with an image as contents for masking a UIView. For the mask I have complex png image. If I apply the image as a view.layer.mask I get the opposite behaviour of what I want. Is there a way to reverse the CAlayer? Here is my code: layerMask = CALayer() guard let layerMask = layerMask else { return } layerMask.contents = #imageLiteral(resourceName: "mask").cgImage view.layer.mask = layerMask // What I would like to to is view.layer.mask = layerMask.inverse. // <--- I have seen several posts on reverse CAShapeLayers and Mutable paths, but nothing where I can reverse a

In ActionScript 3 we can apply a mask of to a visual object like this: SomeVisualObject.mask = maskShapeObject; How can I achieve similar result in Objective-C ? Assume I have two UIImageView objects, I want something like this: imageView1.mask = imageView2; How can I use one UIImageView to mask, or clip the shape of, another? CALayer *maskLayer = [CALayer layer]; UIImage *maskImage = [UIImage imageNamed:@"maskImage.png"]; maskLayer.contents = (id)maskImage.CGImage; maskLayer.bounds = (CGRect){CGPointZero, maskImage.size}; UIImageView *imageViewToMask = [[UIImageView alloc] initWithFrame

I am wondering how to animate the scale of a mask on a uiimageview. Example images attached. The gray boxes are the image background of my uiviewcontroller and is not part of the issue. I assume creation of a uiview subclass that I pass an image, a radius and a center point. And then (?) create a mask, and then animate it back and forth? Can anyone point me in the right direction? The circle can be placed anywhere, at any size, but the image to be revealed is always full screen. Eventually I will add a method to shrink the circle back down. But one step at a time. Thank you for the direction,