transformation

I'm curious what the most performant method of doing string transformations is. Given a n input string and a set of translations, what method is the most efficient in general? I currently use strtr() , but have tested various looping methods, str_replace() with an array, etc. The strtr() method benchmarks the fastest on my system, depending on the translations, but I'm curious if there are faster methods I haven't thought of yet. If it's pertinent, my particular use case involves transforming 2-byte strings into ANSI color sequences for a terminal. Example: // In practice, the number of

I want to convert a dataframe from wide format to long format. Here it is a toy example: mydata <- data.frame(ID=1:5, ZA_1=1:5, ZA_2=5:1,BB_1=rep(3,5),BB_2=rep(6,5),CC_7=6:2) ID ZA_1 ZA_2 BB_1 BB_2 CC_7 1 1 5 3 6 6 2 2 4 3 6 5 3 3 3 3 6 4 4 4 2 3 6 3 5 5 1 3 6 2 There are some variables that will remain as is (here only ID) and some that will be transformed to long format (here all other variables, all ending with _1, _2 or _7) In order to transform it to long format I'm using data.table melt and dcast, a generic way able to detect the variables automatically. Other solutions are welcome too.

How to rename the elements according to a mapping table based on attribute's of the element? Any suggestions would be much appreciated. Maybe a XSLT 2.0 template and modifying the mapping table for better solution? Many thanks in advance Thomas Original XML: <transaction> <records type="1" > <record type="1" > <field number="1" > <item>223</item> </field> <field number="2" > <item>456</item> </field> </record> </records> <records type="14" > <record type="14" > <field number="1" > <item>777</item> </field> <field number="2" > <item>678</item> </field> </record> <record type="14" > <field

How to rename the elements according to a mapping table based on attribute's of the element? Any suggestions would be much appreciated. Maybe a XSLT 2.0 template and modifying the mapping table for better solution? Many thanks in advance Thomas Original XML: <transaction> <records type="1" > <record type="1" > <field number="1" > <item>223</item> </field> <field number="2" > <item>456</item> </field> </record> </records> <records type="14" > <record type="14" > <field number="1" > <item>777</item> </field> <field number="2" > <item>678</item> </field> </record> <record type="14" > <field

I have troubles with XmlResolver class. I have a few XSLT files saved in MS SQL database in xml datatype column. I'm trying to write a XmlResolver class implementation, that would load the text from database instead of from the files. But I'm getting XSLT compiler error. Here is very simple example (text of both input and xslt is hardcoded here): static void Main(string[] args) { string xslt = @"<?xml version=""1.0"" encoding=""utf-8""?> <xsl:stylesheet version=""1.0"" xmlns:xsl=""http://www.w3.org/1999/XSL/Transform"" xmlns:msxsl=""urn:schemas-microsoft-com:xslt"" exclude-result-prefixes="

I'm looking for a SQLAlchemy only solution for converting a dict received from a form submission into a series of rows in the database, one for each field submitted. This is to handle preferences and settings that vary widely across applications. But, it's very likely applicable to creating pivot table like functionality. I've seen this type of thing in ETL tools but I was looking for a way to do it directly in the ORM. I couldn't find any documentation on it but maybe I missed something. Example: Submitted from form: {"UniqueId":1, "a":23, "b":"Hello", "c":"World"} I would like it to be

I try to recreate a script that uses the ImageMagick command "convert" to compose an image. But I want to do the same in PHP using Imagick (version 6.6.2-10). The command is as follows: convert A1.mpc A3.mpc A4.mpc -channel rgba -alpha on -virtual-pixel background -background none -define compose:args=312x26.6776 -compose displace -composite out.mpc I found out that the parameters stand for the following: convert {background} {overlay} [{mask}] [-compose {method}] -composite {result} The PHP Imagick gives me a compose method, but without a mask parameter: http://www.php.net/manual/en/imagick