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Restating the problem - My understanding given the different comments and your updates is the following:

• someone other than you is in possession of data, which as it happens is 2D data, i.e. an Nx2 matrix;
• using the covariance matrix, they are effectively saying something about the joint distribution of these two dimensions, specifically about the variance;
• if they assume a Gaussian distribution, as is implied by your comment regarding 68%, 95% and 99.7% for 1sigma, 2sigma and 3sigma, they can draw ellipses which represent the 2D-normal distribution: these are in fact some of the contour lines associated with the 3D "bell" surface;
• you have obtained the contour lines in a graph and are trying to obtain the covariance matrix (not the original data...);
• you are concerned about the complexity of having to extract the information from each ellipsis.

Partial answer:

• It is impossible to recover the original data, I hope you are already aware of that, but in case you are not let's just note that the covariance matrix is a summary statistic of the data, much like the average, and although it says something about the data many different datasets could happen to have the same summary statistic (the same way many different sets of numbers can give you an average of 10).
• It is possible to somewhat recover the covariance matrix, i.e. the 3 numbers a, b and c in the matrix [a,b;b,c], though the error in doing so will likely be large because of how imprecise the pixel representation is. Essentially, you will be looking for the dimensions of the two axes, for the variances, as well as the angle of one of the axes, for the covariance.
• Unless I am mistaken, under the Gaussian assumption above, you only need to measure this for one of the three ellipses, and then factor by whatever number of sigmas that contour represents. Here you might want to either use the best-defined ellipse, or attempt to use the largest one, which will provide the maximum precision for your measurements (cf. pixelization).
• Also, the problem of finding the axes and angle for the ellipse need not be as complex as what it seems like in your first trials: instead of trying to find the contour of the ellipses, find the bounding rectangle.
• In order to further simplify this process, if your images are color-coded the way you show, then a filter on blue pixels might be enough in terms of image processing. Then simply take the minimum and maximum (x,y) coordinates in order to obtain the bounding rectangle.
• Once the bounding rectangle is obtained, find the equation to your ellipse (that's a question for a math group, but you could start here for example).

Happy filtering!

It probably is log10 of Visual Basic 4: Logarithm(log, lg, ln)

Here's a substitute for VBA:

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The below works for me :

Following my own steps, ive sloved the problem now its DONE like this.

The FieldValue.arrayRemove you are using didn't work in this way. There are two methods to delete data from firestore list. First way is pass element (Not it's index) in FieldValue.arrayRemove which you wants to delete. Second way is get collection from firestore and modify data according to your need and update collection in firestore. Have a look on below code for more understanding.

After counting, you have an array of counts for each value, say:

I think what you're saying is you would make those two calls to setvbuf after a call to scanf, and that on at least one C implementation it had the effect of discarding any "left over" characters, that were not consumed by scanf, in stdin's buffer.

This is not a good way to discard "left over" characters, because the C standard says that setvbuf "may be used only after the stream has been associated with an open file and before any other operation (other than an unsuccessful call to setvbuf) is performed on the stream". (N1570 §7.21.5.6p2.) Violation of this rule should only cause setvbuf to fail, but nonetheless that means it doesn't do what you want.

The best way to do what you want is to not use scanf. Instead, write a real parser for your input and feed it either character by character (using getchar) or line by line (using getline or fgets). A real parser has principled handling of white space (including newline characters) and syntax errors, and therefore never finds itself with "left over" input.

Writing real parsers is unfortunately a book-length topic, so I will say only that sscanf is never useful in a real parser either. (Standard library functions that are useful include strsep, strchr, and the strto* family.)

There are rare circumstances (usually involving processing of interactive input) where you really do have to discard junk at the end of a line. In those circumstances, the way to do it is with this loop:

You already know how to make the author names bold from biblatex: customizing bibliography entry - the same technique can be used for the editorstrg: