Confusing result of Matlab's size() function - image

Very simple issue here I suspect, I am completely new to Matlab (1st day) and have been unable to resolve this by consulting the documentation.
As part of a larger problem, I need to get the dimensions of an image into two variables (row_obj and col_obj for the image object).
According to the documentation:
[m,n] = size(obj)
m: The number of rows in obj.
n: The number of columns in obj.
So, following that, I wrote:
[row_obj, col_obj] = size(object);
disp(row_obj);
disp(col_obj);
disp(size(object));
Which produced the output:
> >> call_i_spy
> 21
>
> 81
>
> 21 27 3
It appears row_obj is correct. If disp(size(object)) produces 21 27 3, then why is col_obj not 27 (the value I need)? What is [row_obj, col_obj] = size(object); actually doing?

Related

how to limit 00 to 99 counter to 60

For a simple starter project I was putting together a 2-7segement display 00 to 99 counter coded on sketch.
//The line below is the array containing all the binary numbers for the digits on a SSD from 0 to 9
const int number[11] = {0b1000000, 0b1111001, 0b0100100, 0b0110000, 0b0011001, 0b0010010, 0b0000010, 0b1111000, 0b0000000, 0b0010000};
I believe that my solution is either to change this part of the code or add another line, I'm just unsure.
Any advice?
I have tried adding another line to set one of the displays to stop at 6 but it didn't compile with the rest of the code.

Dynamic number system in Qlik Sense

My data consists of large numbers, I have a column say - 'amount', while using it in charts(sum of amount in Y axis) it shows something like 1.4G, I want to show them as if is billion then e.g. - 2.8B, or in millions then 80M or if it's in thousands (14,000) then simply- 14k.
I have used - if(sum(amount)/1000000000 > 1, Num(sum(amount)/1000000000, '#,###B'), Num(sum(amount)/1000000, '#,###M')) but it does not show the M or B at the end of the figure and also How to include thousand in the same code.
EDIT: Updated to include the dual() function.
This worked for me:
=dual(
if(sum(amount) < 1, Num(sum(amount), '#,##0.00'),
if(sum(amount) < 1000, Num(sum(amount), '#,##0'),
if(sum(amount) < 1000000, Num(sum(amount)/1000, '#,##0k'),
if(sum(amount) < 1000000000, Num(sum(amount)/1000000, '#,##0M'),
Num(sum(amount)/1000000000, '#,##0B')
))))
, sum(amount)
)
Here are some example outputs using this script to format it:
=sum(amount)
Formatted
2,526,163,764
3B
79,342,364
79M
5,589,255
5M
947,470
947k
583
583
0.6434
0.64
To get more decimals for any of those, like 2.53B instead of 3B, you can format them like '#,##0.00B' by adding more zeroes at the end.
Also make sure that the Number Formatting property is set to Auto or Measure expression.

Spotfire Custom Expression : Calculate (Num/Den) Percentages

I am trying to plot Num/Den type percentages using OVER. But my thoughts does not appear to translate into spotfire custom expression syntax.
Sample Input:
RecordID CustomerID DOS Age Gender Marker
9621854 854693 09/22/15 37 M D
9732721 676557 09/18/15 65 M D
9732700 676557 11/18/15 65 M N
9777003 5514882 11/25/15 53 M D
9853242 1753256 09/30/15 62 F D
9826842 1260021 09/30/15 61 M D
9897642 3375185 09/10/15 74 M N
9949185 9076035 10/02/15 52 M D
10088610 3512390 09/16/15 33 M D
10120650 41598 10/11/15 67 F N
9949185 9076035 10/02/15 52 M D
10088610 3512390 09/16/15 33 M D
10120650 41598 09/11/15 67 F N
Expected Out:
Row Labels D Cumulative_D N Cumulative_N Percentage
Sep 6 6 2 2 33.33%
Oct 2 8 1 3 37.50%
Nov 1 9 1 4 44.44%
My counts are working.
I want to take the same Cumulative_N & Cumulative_D count and plot Percentage over [Axis.X] as a line chart.
Here's what I am using:
UniqueCount(If([Marker]="N",[CustomerID])) / UniqueCount(If([Marker]="D",[CustomerID])) THEN SUM([Value]) OVER (AllPrevious([Axis.X])) as [CumulativePercent]
I understand SUM([Value]) is not the way to go. But I don't know what to use instead.
Also tried the one below as well, but did not:
UniqueCount(If([Marker]="N",[CustomerID])) OVER (AllPrevious([Axis.X])) / UniqueCount(If([Marker]="D",[CustomerID])) OVER (AllPrevious([Axis.X])) as [CumulativePercent]
Can you have a look ?
I found a way to make it work, but it may not fit your overall solution. I should mention i used Count() versus UniqueCount() so that the results would mirror your desired output.
Add a transformation to your current data table
Insert a calculated column Month([DOS]) as [TheMonth]
Set Row Identifers = [TheMonth]
Set value columns and aggregation methods to Count([CustomerID])
Set column titles to [Marker]
Leave the column name pattern as %M(%V) for %C
That will give you a new data table. Then, you can do your cumulative functions. I did them in a cross table to replicate your expected results. Insert a new cross table and set the values to:
Sum([D]), Sum([N]), Sum([D]) OVER (AllPrevious([Axis.Rows])) as [Cumulative_D],
Sum([N]) OVER (AllPrevious([Axis.Rows])) as [Cumulative_N],
Sum([N]) OVER (AllPrevious([Axis.Rows])) / Sum([D]) OVER (AllPrevious([Axis.Rows])) as [Percentage]
That should do it.
I don't know if Spotfire released a fix or based on everyone's inputs I could get the syntax right. But here is the solution that worked for me.
For Columns D & N,
COUNT([CustomerID])
For columns Cumulative_D & Cumulative_N,
Count([CustomerID]) OVER (AllPrevious([Axis.X])) where [Axis.X] is DOS(Month), Marker
For column Percentage,
Count(If([Marker]="N",[CustomerID])) OVER (AllPrevious([Axis.X])) / Count(If([Marker]="D",[CustomerID])) OVER (AllPrevious([Axis.X]))
where [Axis.X] is DOS(Month)

reading in a text file with a SUB (1a) (Control-Z) character in R on Windows

Following on from my query last week reading badly formed csv in R - mismatched quotes, these same CSV files also have embedded control characters such as the ASCII Substitute Character which is decimal 26 or 0x1A. Unfortunately readLines() seems to truncate the line at this character, so I am having difficulty in matching quotes - apart from losing the later fields in these lines!
I have tried to readBin() but I can't get it to read this file. I'm afraid I can't cleanly read this into R to give you an example and I'm having difficulty in creating these in R. Sorry not to be able to demonstrate with a clean example. Thoughts?
Update
Now I'm confused - when I use the code
h3 <- paste('1,34,44.4,"', rawToChar(as.raw(c(as.integer(k1), 26, 65))), '",99')
identical(readLines(textConnection(h3)), h3)
I get TRUE which I find quite surprising!
Update 2
h3
[1] "1,34,44.4,\" HIJK\032A \",99"
> writeLines(h3, 'h3.txt')
> h3a <- readLines('h3.txt')
Warning message:
In readLines("h3.txt") : incomplete final line found on 'h3.txt'
> h3a
[1] "1,34,44.4,\" HIJK"
So readLines() reacts differently when coming from a textConnection() and it silently truncates at the SUB character.
I would be surprised if it makes a difference but I'm on 2.15.2 on Windows-64.
Update 3
Some vague success in solving this...
zb <- file('h3.txt', "rb")
tmp <- readBin(zb, raw(), size=1, n=400) # raw is always of size =1
nchar(tmp)
# [1] 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2
close(zb)
tmp
# [1] 31 2c 33 34 2c 34 34 2e 34 2c 22 20 48 49 4a 4b 1a 41 20 22 2c 39 39 0d 0a
rawToChar(tmp)
# [1] "1,34,44.4,\" HIJK\032A \",99\r\n"
i.e. if I read in the file as binary and convert to character() afterwards it seems to work... this will be tedious for large CSV files...
Could there be a bug in R in incorrectly detecting a Control-Z as end of file on windows??
I think I've figured out a solution - because there appears to be a problem reading a Control-Z in the middle of a file on Windows, we need to read the file in binary / raw mode.
fnam <- 'h3.txt'
tmp.bin <- readBin(fnam, raw(), size=1, n=max(2*file.info(dfnam)$size, 100))=1
tmp.char <- rawToChar(tmp.bin)
txt <- unlist(strsplit(tmp.char, '\r\n', fixed=TRUE))
txt
[1] "1,34,44.4,\" HIJK\032A \",99"
Update
The following better answer was posted by Duncan Murdoch to R-Devel refer. Converting it into a function I get:
sReadLines <- function(fnam) {
f <- file(fnam, "rb")
res <- readLines(f)
close(f)
res
}
I also ran into this problem when I used read.csv with a csv file that contained the SUB or CTRL-Z in the middle of the file.
Solved it with the readr package (if your file is comma separated)
library(readr)
read_csv("h3.txt")
If you have a ; as a separator, then use:
library(readr)
read_csv2("h3.txt")

Checking if pixel belongs to an image

I have written the following function that find if a pixel belongs to an image in matlab.
At the beginning, I wanted to test it as if a number in a set belongs to a vector like the following:
function traverse_pixels(img)
for i:1:length(img)
c(i) = img(i)
end
But, when I run the following commands for example, I get the error shown at the end:
>> A = [ 34 565 456 535 34 54 5 5 4532 434 2345 234 32332434];
>> traverse_pixels(A);
??? Error: File: traverse_pixels.m Line: 2 Column: 6
Unexpected MATLAB operator.
Why is that? How can I fix the problem?
Thanks.
There is a syntax error in the head of your for loop, it's supposed to be:
for i = 1:length(img)
Also, to check if an array contains a specific value you could use:
A = [1 2 3]
if sum(A==2)>0
disp('there is at least one 2 in A')
end
This should be faster since no for loop is included.
for i = 1:length(image)
silly error, not : , it is =

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