run-length-encoding

Creating a code to decompress byte-oriented RLE image

由 孤者浪人 提交于 2019-12-13 03:47:25
问题 I'm trying to create a code to decompress an RLE Byte-Oriented image from a PostScript File I've already tried solutions found around the web and also tried to build my own ; but none of them produced the result i need. After decompressing the rle image, i should have an RAW image i can open on photoshop (informing width, height and number of channels). However when i try to open the extracted image it doesn't work ; only a black output is show. My inputs are an Binary ASCII Encoded file

Replace sequence of identical values of length > 2

由 萝らか妹 提交于 2019-12-12 14:35:02
问题 I have a sensor that measures a variable and when there is no connection it returns always the last value seen instead of NA . So in my vector I would like to replace these identical values by an imptuted value (for example with na.approx ). set.seed(3) vec <- round(runif(20)*10) #### [1] 2 8 4 3 6 6 1 3 6 6 5 5 5 6 9 8 1 7 9 3 But I want only the sequences bigger than 2 (3 or more identical numbers) because 2 identical numbers can appear naturally. (in previous example the sequence to tag

C++ and RLE for sequences of symbols

由 不问归期 提交于 2019-12-12 04:41:53
问题 I have difficulties with how to use RLE on sequences of symbols. For example, I can do RLE encoding on strings like "ASSSAAAEERRRRRRRR" which will be transformed to: "A1S3A3E2R8". But I'd like to perform RLE on strings like "XXXYYYYY(1ADEFC)(EDCADD)(1ADEFC)(1ADEFC)(1ADEFC)" which will be transformed to: "X3Y5(1ADEFC)1(EDCADD)1(1ADEFC)3" Is there is a way to reach it? This job becomes a bit easer because long strings always follows in brackets. Could give an advice to do this in C++? If there

Calculating number of three consecutive values above a threshold (in raster stack)

由 老子叫甜甜 提交于 2019-12-12 04:34:14
问题 I need to compute number of three consecutive days when value of each pixel in a raster stack ( x ) is above a given threshold (defined by another raster y ). I tried using rle for the purpose with calc as follows after stacking x and y together into new raster a : library(raster) fn<-function(a) with(rle(a), sum(lengths>=3 & values>a[[nlayers(a)]])) calc(b,fn) However, I am getting the error: Error in .calcTest(x[1:5], fun, na.rm, forcefun, forceapply) : cannot use this function Reproducible

Get length of runs of missing values in vector

由 妖精的绣舞 提交于 2019-12-10 16:14:50
问题 What's a clever (i.e., not a loop) way to get the length of each spell of missing values in a vector? My ideal output is a vector that is the same length, in which each missing value is replaced by the length of the spell of missing values of which it was a part, and all other values are 0's. So, for input like: x <- c(2,6,1,2,NA,NA,NA,3,4,NA,NA) I'd like output like: y <- c(0,0,0,0,3,3,3,0,0,2,2) 回答1: One simple option using rle : m <- rle(is.na(x)) > rep(ifelse(m$values,m$lengths,0),times =

Count consecutive values in groups with condition with dplyr and rle

由 半世苍凉 提交于 2019-12-08 01:20:31
问题 My question is very similar to the one posed below, however I want to add an additional command to return only cases when a sequence has more than 2 consecutive values. How do I count the number of consecutive "success" (i.e. 1 in $consec) when a given sequence run has more than 2 consecutive numbers, within a given Era and a given Year? Similar question to: Summarize consecutive failures with dplyr and rle . For comparison, I've modified the example used in that question: library(dplyr) df <

Implementing run-length encoding

由 萝らか妹 提交于 2019-12-07 16:08:35
问题 I've written a program to perform run length encoding. In typical scenario if the text is AAAAAABBCDEEEEGGHJ run length encoding will make it A6B2C1D1E4G2H1J1 but it was adding extra 1 for each non repeating character. Since i'm compressing BMP files with it, i went with an idea of placing a marker "$" to signify the occurance of a repeating character, (assuming that image files have huge amount of repeating text). So it'd look like $A6$B2CD$E4$G2HJ For the current example it's length is the

Count consecutive values in groups with condition with dplyr and rle

由 佐手、 提交于 2019-12-06 08:58:26
My question is very similar to the one posed below, however I want to add an additional command to return only cases when a sequence has more than 2 consecutive values. How do I count the number of consecutive "success" (i.e. 1 in $consec) when a given sequence run has more than 2 consecutive numbers, within a given Era and a given Year? Similar question to: Summarize consecutive failures with dplyr and rle . For comparison, I've modified the example used in that question: library(dplyr) df <- data.frame(Era=c(1,1,1,1,1,1,1,1,1,1),Year = c(1,2,2,3,3,3,3,3,3,3), consec = c(0,0,1,0,1,1,0,1,1,1))

Compression Program in C

由 让人想犯罪 __ 提交于 2019-12-06 07:16:45
问题 I want to compress a series of characters. For example if i type Input : FFFFFBBBBBBBCCBBBAABBGGGGGSSS (27 x 8 bits = 216 bits) Output: F5B7C2B3A2B2G5S3 (14 x 8 bits = 112bits) So far this is what i have, i can count the number of Characters in the Array. But the most important task is to count them in the same sequence. I can't seem to figure that out :( Ive stared doing C just a few weeks back, i have knowledge on Array, pointers, ASCII value but in any case can't seem to count these

Implementing run-length encoding

由 假装没事ソ 提交于 2019-12-06 00:53:14
I've written a program to perform run length encoding. In typical scenario if the text is AAAAAABBCDEEEEGGHJ run length encoding will make it A6B2C1D1E4G2H1J1 but it was adding extra 1 for each non repeating character. Since i'm compressing BMP files with it, i went with an idea of placing a marker "$" to signify the occurance of a repeating character, (assuming that image files have huge amount of repeating text). So it'd look like $A6$B2CD$E4$G2HJ For the current example it's length is the same, but there's a noticable difference for BMP files. Now my problem is in decoding. It so happens
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