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Read an Excel file directly from a R script
... directly into R? Or should I first export the data to a text- or CSV file and import that file into R?
12 Answers
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Signed to unsigned conversion in C - is it always safe?
...unsigned values, resulting in a large result (depending on the values of u and i).
Long Answer
According to the C99 Standard:
6.3.1.8 Usual arithmetic conversions
If both operands have the same type, then no further conversion is needed.
Otherwise, if both operands have signed intege...
Which cryptographic hash function should I choose?
...Indeed, MD5 is often still used in applications where the smaller key size and speed are beneficial. That said, due to its flaws, researchers recommend the use of other hash functions in new scenarios.
SHA1 has a flaw that allows collisions to be found in theoretically far less than the 2^80 steps ...
android:drawableLeft margin and/or padding
...ssible to set the margin or padding for the image which we added with the android:drawableLeft ?
18 Answers
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Retrieving Android API version programmatically
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As described in the Android documentation, the SDK level (integer) the phone is running is available in:
android.os.Build.VERSION.SDK_INT
The class corresponding to this int is in the android.os.Build.VERSION_CODES class.
Code example:
if (a...
Writing to an Excel spreadsheet
... to write some data from my program to a spreadsheet. I've searched online and there seem to be many packages available (xlwt, XlsXcessive, openpyxl). Others suggest to write to a .csv file (never used CSV and don't really understand what it is).
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Is floating point math broken?
...is like this. In most programming languages, it is based on the IEEE 754 standard. The crux of the problem is that numbers are represented in this format as a whole number times a power of two; rational numbers (such as 0.1, which is 1/10) whose denominator is not a power of two cannot be exactly re...
How to check command line parameter in “.bat” file?
... I need to have a ".bat" file where I need to check if user enters any command-line parameter or not. If does then if the parameter equals to -b then I will do something otherwise I will flag "Invalid input". If user does not enter any command-line parameter then I will do something. I have crea...
Unit Test? Integration Test? Regression Test? Acceptance Test?
...er has not introduced any errors.
Regression testing - after integrating (and maybe fixing) you should run your unit tests again. This is regression testing to ensure that further changes have not broken any units that were already tested. The unit testing you already did has produced the unit te...
How would Git handle a SHA-1 collision on a blob?
This probably never happened in the real-world yet, and may never happen, but let's consider this: say you have a git repository, make a commit, and get very very unlucky: one of the blobs ends up having the same SHA-1 as another that is already in your repository. Question is, how would Git handle ...