I had created a simple test code for CAN using PIC18F4580. Which consists of 2 nodes sending data between each other. Uses 11-bit standard ID for communication. Node-1 is given ID of 10 and Node-2 is given ID of 20. I tried to display the registers like COMSTAT, TXB0CON, RXB0CON on the LCD here are the register contents.
COMSTAT = 0x00
TXB0CON = 0x00
RXB0CON = 0x01
When key is pressed it will first show the contents of COMSTAT, TXB0CON and RXB0CON on LCD in sequence.
Then at the end it will put the message frame ID = XX, Data = NDx on CAN Bus
Node-1 puts ND2 on data field D0(N), D1(D) and D2(2) with DLC is 3 and ID = 20.
Similarly Node-2 puts ND1 on data field D0(N), D1(D) and D2(1) with DLC is 3 and ID = 10 (Please refer the Test code given).
Both the nodes send the data but Node-1 is only receiving. And showing ID = 00 instead of 10, and received data is displayed as some garbage on LCD.
Test code link
Related
Basic stuff that I can't figure out or find in internet:
The little code I'm using for tests is simple:
require("ex")
a = true
b = nil
while (a == true) do
b = io.read()
ex.sleep(5)
print(b)
end
Very simple. If I input "1" (I am using notepad++ and windows command prompt), it will wait 5 seconds and print it, then repeat. But my problem is... If I input more numbers during the 5 seconds of sleeping, it all will be executed automatically, in order, when the sleep ends.
Is it possible to stop that? I don't want any input being read during that time. Where these "ghost" inputs are stored?
You can control reading by means of "buffer size" argument in bytes:
b = io.read(1)
In this case reading completes after the first byte was taken from input. Rest input bytes will be available for the next "read" statement.
Important note: if you input "1" and press "Enter" then there will be 3 bytes for reading (including "\r\n").
See https://www.lua.org/pil/21.1.html for details.
In addition, you want to know a way to clean input buffer before next reading. This is easy: use io.read("*line") statement as follows:
b = io.read("*line") -- suppose, input is: "1234"
b = string.sub(b, 0, 1)
print(b) -- prints 1
b = io.read("*line") -- suppose, input is: "567"
b = string.sub(b, 0, 1)
print(b) -- prints 5
b = io.read("*line") -- suppose, input is: ""
b = string.sub(b, 0, 1)
print(b) -- prints empty string
io.read("*line") gets whole line from input, but you can take only the first character from it.
I'm fairly new to Fortran and try reading in 3D (80000*100*10) single precision NetCDF data (however I'd just read it 2D like (80000,100,1st)). I would need to convert them into double precision for some further code not shown below.
The .nc-File which I create to check if the reading/writing works does contain only "0" if I use real single precision for all NF90-functions as well as the variable 'values'.
It does contain mostly "0" and several weird numbers which don't seem to relate in a conceivable way to the input data if I use double precision (code shown below). At least I get any output in my nc file this way.
I don't get any compiling errors {nor error codes in 'STATUS' if I check for specific lines after NF90 functions. Update: That was mistaken}. Input_test.nc gets created exactly as expected regarding dimensions, but not regarding the actual values.
My code is:
PROGRAM read
Implicit None
INCLUDE 'netcdf.inc'
INTEGER :: NCID, horstart, verstart, horlen, verlen, horcount, vercount, STATUS, STATUS2
REAL(kind=8), DIMENSION(80000,100) :: values
horstart = 1
verstart = 1
horcount = 80000 !!(tried to use this instead of horlen, doesn't change anything)
vercount = 100 !!(tried to use this instead of verlen, doesn't change)
varname = 'pres'
!! get input data
STATUS = NF90_OPEN('my_valid_path/file.nc', 0, NCID)
STATUS = NF90_INQ_DIMID(NCID, 'ncells', horid)
STATUS = NF90_INQ_DIMID(NCID, 'height', verid)
STATUS = NF90_INQ_DIMLEN(NCID,horid,horlen)
STATUS = NF90_INQ_DIMLEN(NCID,verid,verlen)
STATUS = NF90_INQ_VARID(NCID,varname,varid)
STATUS = NF90_GET_VARA_DOUBLE(NCID,varid,[horstart,verstart,1],[horlen,verlen,1],values)
STATUS = NF90_CLOSE(NCID)
STATUS = NF90_CREATE ('some_path/input_test.nc', 0, ncid);
STATUS = NF90_DEF_DIM (ncid, 'hor',horcount, dimhor)
STATUS = NF90_DEF_DIM (ncid, 'ver',vercount, dimver)
STATUS = NF90_DEF_DIM (ncid, '1d',1, dimcode)
STATUS = NF90_DEF_VAR(ncid,'pres',NF90_DOUBLE,2,[dimhor,dimver],pres_id)
STATUS = NF90_DEF_VAR(ncid,'status',NF90_INT,1,dimcode,stat_id)
STATUS = NF90_ENDDEF(ncid)
STATUS = NF90_PUT_VARA_DOUBLE(ncid,pres_id,[horstart,verstart],[horcount,vercount],values)
STATUS = NF90_PUT_VARA_INT(ncid,stat_id,1,1,STATUS2)
STATUS = NF90_CLOSE(ncid)
The nc file I read from doesn't contain any zeroes, not even in the 3rd dimension. The Output file however does contain a lot zeroes, it is not empty though.
Example input: 0,095213220 0,099325478 0,10358732 0,10800611 0,11259078 0,11734842 0,12228279 0,12740466 0,13271827 0,13822863 0,14394356
Example output: 0 0 0 0 0 0,000493943283800036 0,000594558776356280 0,000234268474741839 2,88491937681101e-05 2,09666131608306e-16 7,30948746534081e-20
I'm probably doing something stupid, but I went temporarily out of ideas what to check for.
UPDATE: Thoroughly checking the error codes saved in STATUS did give a non-zero match at NF90_GET_VARA_DOUBLE/(also REAL). Getting back to this tomorrow.
With error handler I came to the conclusion that the above code works. The errors eventually came from a spelling mistake of the variables I tried to read from.
I have a data set that allows linking friends (i.e. observing peer groups) and thereby one can observe the characteristics of an individual's friends. What I have is an 8 digit identifier, id, each id's friend id's (up to 10 friends), and then many characteristic variables.
I want to take an individual and create a variables that are the foreign born status of each friend.
I already have an indicator for each person that is 1 if foreign born. Below is a small example, for just one friend. Notice, MF1 means male friend 1 and then MF1id is the id number for male friend 1. The respondents could list up to 5 male friends and 5 female friends.
So, I need Stata to look at MF1id and then match it down the id column, then look over to f_born for that matched id, and finally input the value of f_born there back up to the original id under MF1f_born.
edit: I did a poor job of explaining the data structure. I have a cross section so 1 observation per unique id. Row 1 is the first 8 digit id number with all the variables following over the row. The repeating id numbers are between the friend id's listed for each person (mf1id for example) and the id column. I hope that is a bit more clear.
Kevin Crow wrote vlookup that makes this sort of thing pretty easy:
use http://www.ats.ucla.edu/stat/stata/faq/dyads, clear
drop team y
rename (rater ratee) (id mf1_id)
bys id: gen f_born = mod(id,2)==1
net install vlookup
vlookup mf1_id, gen(mf1f_born) key(id) value(f_born)
So, Dimitriy's suggestion of vlookup is perfect except it will not work for me. After trying vlookup with both my data set, the UCLA data that Dimitriy used for his example, and a toy data set I created vlookup always failed at the point the program attempts to save a temp file to my temp folder. Below is the program for vlookup. Notice its sets tempfile file, manipulates the data, and then saves the file.
*! version 1.0.0 KHC 16oct2003
program define vlookup, sortpreserve
version 8.0
syntax varname, Generate(name) Key(varname) Value(varname)
qui {
tempvar g k
egen `k' = group(`key')
egen `g' = group(`key' `value')
local k = `k'[_N]
local g = `g'[_N]
if `k' != `g' {
di in red "`value' is unique within `key';"
di in red /*
*/ "there are multiple observations with different `value'" /*
*/ " within `key'."
exit 9
}
preserve
tempvar g _merge
tempfile file
sort `key'
by `key' : keep if _n == 1
keep `key' `value'
sort `key'
rename `key' `varlist'
rename `value' `generate'
save `file', replace
restore
sort `varlist'
joinby `varlist' using `file', unmatched(master) _merge(`_merge')
drop `_merge'
}
end
exit
For some reason, Stata gave me an error, "invalid file," at the save `file', replace point. I have a restricted data set with requirments to point all my Stata temp files to a very specific folder that has an erasure program sweeping it every so often. I don't know why this would create a problem but maybe it is, I really don't know. Regardless, I tweaked the vlookup program and it appears to do what I need now.
clear all
set more off
capture log close
input aid mf1aid fborn
1 2 1
2 1 1
3 5 0
4 2 0
5 1 0
6 4 0
7 6 1
8 2 .
9 1 0
10 8 1
end
program define justlinkit, sortpreserve
syntax varname, Generate(name) Key(varname) Value(name)
qui {
preserve
tempvar g _merge
sort `key'
by `key' : keep if _n ==1
keep `key' `value'
sort `key'
rename `key' `varlist'
rename `value' `generate'
save "Z:\Jonathan\created data sets\justlinkit program\fchara.dta",replace
restore
sort `varlist'
joinby `varlist' using "Z:\Jonathan\created data sets\justlinkit program\fchara.dta", unmatched(master) _merge(`_merge')
drop `_merge'
}
end
// set trace on
justlinkit mf1aid, gen(mf1_fborn) key(aid) value(fborn)
sort aid
list
Well, this fixed my problem. Thanks to all who responded I would not have figured this out without you.
I have forked many child processes and assigned priority and core to each of them. Porcess A executes at period of 3 sec and process B at a period of 6 sec. I want them to execute in such a way that the higher priority processes should preempt lower priority ones only at predefined points and tried to acheive it with semaphores. I have used this same code snippets within the 2 processes with different array values in both.
'bubblesort_desc()' sorts the array in descending order and prints it. 'bubblesort_asc()' sorts in ascending order and prints.
while(a<3)
{
printf("time in sort1.c: %d %ld\n", (int)request.tv_sec, (long int)request.tv_nsec);
int array[SIZE] = {5, 1, 6 ,7 ,9};
semaphore_wait(global_sem);
bubblesort_desc(array, SIZE);
semaphore_post(global_sem);
semaphore_wait(global_sem);
bubblesort_asc(array, SIZE);
semaphore_post(global_sem);
semaphore_wait(global_sem);
a++;
request.tv_sec = request.tv_sec + 6;
request.tv_nsec = request.tv_nsec; //if i add 1ms here like an offset to the lower priority one, it works.
semaphore_post(global_sem);
semaphore_close(global_sem); //close the semaphore file
//sleep for the rest of the time after the process finishes execution until the period of 6
clk = clock_nanosleep(CLOCK_MONOTONIC, TIMER_ABSTIME, &request, NULL);
if (clk != 0 && clk != EINTR)
printf("ERROR: clock_nanosleep\n");
}
I get the output like this whenever two processes get activated at the same time. For example at time units of 6, 12,..
time in sort1.c: 10207 316296689
time now in sort.c: 10207 316296689
9
99
7
100
131
200
256
6
256
200
5
131
100
99
1
1
5
6
7
9
One process is not supposed to preempt the other while one set of sorted list is printing. But it's working as if there are no semaphores. I defined semaphores as per this link: http://linux.die.net/man/3/pthread_mutexattr_init
Can anyone tell me what can be the reason for that? Is there a better alternative than semaphores?
Its printf that's causing the ambiguous output. If the results are printed without '\n' then we get a more accurate result. But its always better to avoid printf statements for real time applications. I used trace-cmd and kernelshark to visualize the behaviour of the processes.
I have a rinex file and is shown here..an image showing the first part of rinex file
http://imageshack.us/photo/my-images/593/65961409.jpg
The data (AOPR Rinex file) is downloaded from the site after entering a year and a day.
http://www.naic.edu/aisr/GPSTEC/gpstec.html
I want to open this file as a matrix in matlab for further processing..After the end of header at the 42nd line the time information is on 43 rd line. Then data starts. But time information is coming again after some rows say 64 the line, which should be discarded. Header should also be discarded. Also the last column is coming below the first column as a second row which should be transferred to the last column. Totally there are 55700 rows. Kindly help me with this.
I suspect the last column appearing on the line below it is just an artifact of how large the window of your text reader is...
For the rest, I think a trial-and-error loop is in place here:
fid = fopen('test.txt','r');
C = {};
while ~feof(fid)
% read lines with dictated format.
D = textscan(fid, '%d %d %d %d');
% this will fail on headerlines, empty lines, etc.
if isempty(D{1})
% in those cases, advance the file pointer by one line
fgetl(fid);
else
% if that's not the case, save the lines thus read
C = [C;D]; %#ok
end
end
fclose(fid);
% Post-process: concatenate all sub-arrays into one
C = arrayfun(#(ii) cat(1, C{:,ii}), 1:size(C,2), 'UniformOutput', false);
This works, at least with my test.txt:
header
random
garbage
1 2 3 4
4 5 6 7
4 6 7 8
more random garbage
2 5 6 7
5 6 7 8
8 6 3 7
I suspect the last column appearing on the line below it is just an artifact of how large >the window of your text reader is...
For the rest, I think a trial-and-error loop is in place here
Dear Rody I don't have any matlab background and just a beginner. It is actually a Rinex file..with 2780 epochs and 6 observables with 30 satellite values..Decoding it in matlab is tough. That is the problem. You can read a sample code at
http://web.ics.purdue.edu/~tdauterm/EAS591/Lab7/read_rinexo.m
But the problem is that the observables are six and there only 5 in the m-file which also is not in the correct order. I need C1 P2 L1 L2 S1 S2...but the code at the link gives L1 L2 C1 P1 P2. :( Can you just correct that..Then it will be a great help..