I have a q table in which no. of non keyed columns is variable. Also, these column names contain an integer in their names. I want to perform some function on these columns without actually using their actual names
How can I achieve this ?
For Example:
table:
a | col10 col20 col30
1 | 2 3 4
2 | 5 7 8
// Assume that I have numbers 10, 20 ,30 obtained from column names
I want something like **update NewCol:10*col10+20*col20+30*col30 from table**
except that no.of columns is not fixed so are their inlcluded numbers
We want to use a functional update (simple example shown here: http://www.timestored.com/kdb-guides/functional-queries-dynamic-sql#functional-update)
For this particular query we want to generate the computation tree of the select clause, i.e. the last part of the functional update statement. The easiest way to do that is to parse a similar statement then recreate that format:
q)/ create our table
q)t:([] c10:1 2 3; c20:10 20 30; c30:7 8 9; c40:0.1*4 5 6)
q)t
c10 c20 c30 c40
---------------
1 10 7 0.4
2 20 8 0.5
3 30 9 0.6
q)parse "update r:(10*c10)+(20*col20)+(30*col30) from t"
!
`t
()
0b
(,`r)!,(+;(*;10;`c10);(+;(*;20;`col20);(*;30;`col30)))
q)/ notice the last value, the parse tree
q)/ we want to recreate that using code
q){(*;x;`$"c",string x)} 10
*
10
`c10
q){(+;x;y)} over {(*;x;`$"c",string x)} each 10 20
+
(*;10;`c10)
(*;20;`c20)
q)makeTree:{{(+;x;y)} over {(*;x;`$"c",string x)} each x}
/ now write as functional update
q)![t;();0b; enlist[`res]!enlist makeTree 10 20 30]
c10 c20 c30 c40 res
-------------------
1 10 7 0.4 420
2 20 8 0.5 660
3 30 9 0.6 900
q)update r:(10*c10)+(20*c20)+(30*c30) from t
c10 c20 c30 c40 r
-------------------
1 10 7 0.4 420
2 20 8 0.5 660
3 30 9 0.6 900
I think functional select (as suggested by #Ryan) is the way to go if the table is quite generic, i.e. column names might varies and number of columns is unknown.
Yet I prefer the way #JPC uses vector to solve the multiplication and summation problem, i.e. update res:sum 10 20 30*(col10;col20;col30) from table
Let combine both approach together with some extreme cases:
q)show t:1!flip(`a,`$((10?2 3 4)?\:.Q.a),'string 10?10)!enlist[til 100],0N 100#1000?10
a | vltg4 pnwz8 mifz5 pesq7 fkcx4 bnkh7 qvdl5 tl5 lr2 lrtd8
--| -------------------------------------------------------
0 | 3 3 0 7 9 5 4 0 0 0
1 | 8 4 0 4 1 6 0 6 1 7
2 | 4 7 3 0 1 0 3 3 6 4
3 | 2 4 2 3 8 2 7 3 1 7
4 | 3 9 1 8 2 1 0 2 0 2
5 | 6 1 4 5 3 0 2 6 4 2
..
q)show n:"I"$string[cols get t]inter\:.Q.n
4 8 5 7 4 7 5 5 2 8i
q)show c:cols get t
`vltg4`pnwz8`mifz5`pesq7`fkcx4`bnkh7`qvdl5`tl5`lr2`lrtd8
q)![t;();0b;enlist[`res]!enlist({sum x*y};n;enlist,c)]
a | vltg4 pnwz8 mifz5 pesq7 fkcx4 bnkh7 qvdl5 tl5 lr2 lrtd8 res
--| -----------------------------------------------------------
0 | 3 3 0 7 9 5 4 0 0 0 176
1 | 8 4 0 4 1 6 0 6 1 7 226
2 | 4 7 3 0 1 0 3 3 6 4 165
3 | 2 4 2 3 8 2 7 3 1 7 225
4 | 3 9 1 8 2 1 0 2 0 2 186
5 | 6 1 4 5 3 0 2 6 4 2 163
..
You can create a functional form query as #Ryan Hamilton indicated, and overall that will be the best approach since it is very flexible. But if you're just looking to add these up, multiplied by some weight, I'm a fan of going through other avenues.
EDIT: missed that you said the number in the columns name could vary, in which case you can easily adjust this. If the column names are all prefaced by the same number of letters, just drop those and then parse the remaining into int or what have you. Otherwise if the numbers are embedded within text, check out this other question
//Create our table with a random number of columns (up to 9 value columns) and 1 key column
q)show t:1!flip (`$"c",/:string til n)!flip -1_(n:2+first 1?10) cut neg[100]?100
c0| c1 c2 c3 c4 c5 c6 c7 c8 c9
--| --------------------------
28| 3 18 66 31 25 76 9 44 97
60| 35 63 17 15 26 22 73 7 50
74| 64 51 62 54 1 11 69 32 61
8 | 49 75 68 83 40 80 81 89 67
5 | 4 92 45 39 57 87 16 85 56
48| 88 34 55 21 12 37 53 2 41
86| 52 91 79 33 42 10 98 20 82
30| 71 59 43 58 84 14 27 90 19
72| 0 99 47 38 65 96 29 78 13
q)update res:sum (1+til -1+count cols t)*flip value t from t
c0| c1 c2 c3 c4 c5 c6 c7 c8 c9 res
--| -------------------------------
28| 3 18 66 31 25 76 9 44 97 2230
60| 35 63 17 15 26 22 73 7 50 1551
74| 64 51 62 54 1 11 69 32 61 1927
8 | 49 75 68 83 40 80 81 89 67 3297
5 | 4 92 45 39 57 87 16 85 56 2582
48| 88 34 55 21 12 37 53 2 41 1443
86| 52 91 79 33 42 10 98 20 82 2457
30| 71 59 43 58 84 14 27 90 19 2134
72| 0 99 47 38 65 96 29 78 13 2336
q)![t;();0b; enlist[`res]!enlist makeTree 1+til -1+count cols t] ~ update res:sum (1+til -1+count cols t)*flip value t from t
1b
q)\ts do[`int$1e4;![t;();0b; enlist[`res]!enlist makeTree 1+til 9]]
232 3216j
q)\ts do[`int$1e4;update nc:sum (1+til -1+count cols t)*flip value t from t]
69 2832j
I haven't tested this on a large table, so caveat emptor
Here is another solution which is also faster.
t,'([]res:(+/)("I"$(string tcols) inter\: .Q.n) *' (value t) tcols:(cols t) except keys t)
By spending some time, we can decrease the word count as well. Logic goes like this:
a:"I"$(string tcols) inter\: .Q.n
Here I am first extracting out the integers from column names and storing them in a vector. Variable 'tcols' is declared at the end of query which is nothing but columns of table except key columns.
b:(value t) tcols:(cols t) except keys t
Here I am extracting out each column vector.
c:(+/) a *' b
Multiplying each column vector(var b) by its integer(var a) and adding corresponding
values from each resulting list.
t,'([]res:c)
Finally storing result in a temp table and joining it to t.
Related
20 4 4 74 20 20 74 85 85 85 2 1
A = 36 1 1 11 36 36 11 66 66 66 4 1
77 1 1 15 77 77 15 11 11 11 1 4
3 4 2 6 7 8 10 10 15 17 1 5
20 4 85
B = 36 1 66
77 1 11
How from the matrix A, I can extract the submatrix whose coloumns contains the vectors B(:,i): [20 36 77] , [4 1 1] and [85 66 11]?
The desired result:
20 4 4 20 20 85 85 85
36 1 1 36 36 66 66 66
77 1 1 77 77 11 11 11
3 4 2 7 8 10 15 17
Now that you've explained what you want, transpose the matrices, select only the three top rows of A, and then use the third argument of ismember to specify that you want to compare entire rows:
A(:,ismember(A(1:3,:).', B.', 'rows').')
20 4 4 20 20 85 85 85
36 1 1 36 36 66 66 66
77 1 1 77 77 11 11 11
3 4 2 7 8 10 15 17
20 4 4 74 20 20 74 85 85 85
A = 36 1 1 11 36 36 11 66 66 66
77 1 1 15 77 77 15 11 11 11
3 4 2 6 7 8 10 10 15 17
how from the matrix A, I can extract the submatrix whose fourth line (end line) contains only the values [3 6 10]?
for a single value, I do:
B=A(:,A(4,:)==10)
but I do not know how to do this for several values.
Use ismember -
search_array = [3 6 10]
subA = A(:,ismember(A(end,:),search_array))
Or bsxfun -
subA = A(:,any(bsxfun(#eq,A(end,:),search_array(:)),1))
I have created graphs using filledcurves. Now, the graphs looks bad because long range of data.
This is my data:
a b c d e f g h i
201312 49 26 34 30 14 25 9 4 1
201311 38 22 47 30 9 9 4 3 1
201310 44 24 43 38 9 14 5 7 0
201309 65 18 33 39 15 12 4 5 1
201308 42 31 44 30 5 11 0 2 2
201307 58 27 35 29 8 4 2 4 2
201306 30 22 15 17 2 6 3 4 0
201305 61 52 20 16 11 12 2 3 0
201304 62 60 33 18 13 9 5 6 0
201303 43 53 49 27 9 11 7 0 0
201302 31 30 42 27 10 8 4 2 0
201301 42 30 20 47 9 13 3 2 1
201212 26 19 39 24 9 11 0 0 0
201211 26 26 30 28 1 2 0 2 1
201210 55 46 34 30 13 5 0 2 1
201209 56 31 27 28 27 13 2 4 1
201208 48 75 38 46 22 10 0 1 0
201207 60 56 37 47 19 11 2 1 0
201206 60 41 37 28 17 12 5 1 0
201205 49 43 38 46 15 16 2 2 0
201204 43 50 36 33 4 7 3 0 2
201203 49 63 35 43 16 7 1 2 0
201202 43 59 59 52 16 13 3 4 1
201201 51 44 30 37 20 9 4 1 0
201112 50 38 36 36 8 2 3 1 1
201111 75 35 30 36 16 7 3 3 1
201110 68 53 41 27 11 15 1 2 1
201109 68 46 48 47 16 19 4 0 1
201108 45 41 20 36 17 10 1 0 0
201107 48 34 30 24 13 7 3 3 1
201106 49 29 24 25 5 6 0 3 0
201105 45 35 21 37 1 7 2 1 0
201104 53 35 23 18 4 6 1 5 1
201103 58 42 20 18 6 4 1 0 4
201102 54 32 19 20 4 10 0 2 0
201101 42 41 21 28 3 6 1 2 1
and this is my gnuplot file:
set terminal postscript eps color font 20
set xtics 1 out
set tics front
#set style fill transparent solid 0.5 noborder
set key below autotitle columnheader
set ylabel "Count"
set xlabel "across time"
set output 't1.eps'
set title "t1-Across time of Aspects"
set xtics 1
plot for [i=10:2:-1] \
"< awk 'NR==1 {print \"year\",$".(i-1)."} NR>=2 {for (i=2; i<=".i."; i++) \
{sum+= $i} {print $1, sum; sum=0} }' data.dat" \
using (column(2)):xtic(1) with filledcurves x1 t column(2)
When I add time in xdata:
set xdata time
set timefmt "%Y%m"
set xtics format "%b"
Erros message:
Need full using spec for x time data
Is the Errors because of my date format? I have googling this and do not have any answer about it. Please give me suggestion about this.
In the script you show, you specify only a single column in the using statement (besides the xtic). That means, that this value is taken as y-value and the row number is implicitely used as x-value.
When using time data, you must explicitely specify all columns which are needed for the plotting style, there is no assumption about what might be the first column. Use:
set key below autotitle columnheader
set ylabel "Count"
set xlabel "across time"
set tics front
set xdata time
set timefmt "%Y%m"
set xtics format "%b'%y"
set autoscale xfix
plot for [i=10:2:-1] \
"< awk 'NR==1 {print \"year\",$".(i-1)."} NR>=2 {for (i=2; i<=".i."; i++) \
{sum+= $i} {print $1, sum; sum=0} }' data.dat" \
using 1:2 with filledcurves x1 t column(2)
Result with 4.6.4:
I guess you don't want xtic(1) if you have time data and specify the x format.
I have been implementing this paper:
http://www.tandfonline.com/doi/abs/10.1080/03610918.2011.575506#.UrijOLS_UhI
I can send a copy should anybody require it.
I think that my implementation is correct but I get significantly different answers to those given in the paper:
My results
B0 0.0470
B1 2.1635
B2 1.1560
B3 0.7451
B4 0.4931
Results in paper
B0 0.1228
B1 2.1630
B2 1.1552
B3 0.7444
B4 0.4922
As you can see B0 is way off while the remaining Beta values are only correct to decimal places which is not good enough. Could the difference be done to differences in the versions of Matlab used? I use R2011a where as the author uses Matlab 7.0?
function [b_LRRE]=LRRE(y,x)
[n, p]=size(x);
dim=1;
b=x\y;
sig_ols_sq=((y-x*b)'*(y-x*b))/(n-p);
econFlag=0;
[U,sigma,V] = svd(x,econFlag);
d=zeros(p,1);
d=diag(d);
alpha=V'*b;
Delta=sigma.^2;
I=ones(p,1);
I=diag(I);
for jj=1:50
for ii=1:p
d(ii,ii)=(Delta(ii,ii)*(alpha(ii)^2-sig_ols_sq))/(sig_ols_sq+Delta(ii,ii)*alpha(ii)^2);
end
A=pinv(Delta+I)*(Delta+d);
b_LRRE=V*A*V'*b;
alpha=V'*b_LRRE;
end
end
Here is the data
78.5 1 7 26 6 60
74.3 1 1 29 15 52
104.3 1 11 56 8 20
87.6 1 11 31 8 47
95.9 1 7 52 6 33
109.2 1 11 55 9 22
102.7 1 3 71 17 6
72.5 1 1 31 22 44
93.1 1 2 54 18 22
115.9 1 21 47 4 26
83.8 1 1 40 23 34
113.3 1 11 66 9 12
109.4 1 10 68 8 12
We have a MxN matrix and a constrain cstrn = 100;.
The constrain is the summarize limit of column's elements (per column):
sum(matrix(:,:))<=cstrn.
For a given example as the following:
Columns 1 to 5:
15 18 -5 22 19
50 98 -15 39 -8
70 -15 80 45 38
31 52 9 80 72
-2 63 52 71 6
7 99 32 58 41
I want to find the max number of element per column who fulfill this constrain.
How can i summarize every column element with the others elements in same column and find which sum combinations uses the max number of elements per column?
In the given example solution is:
4 3 5 2 5
where
column 1: 15 + 50 + 31 +7 +(-2)
column 2: 18 +(-15) + 52 or 63 etc.
Thank you in advance.
Since it is always easier to fit small elements into a sum, you can do a sort, followed by the cumulative sum:
m= [
15 18 -5 22 19
50 98 -15 39 -8
70 -15 80 45 38
31 52 9 80 72
-2 63 52 71 6
7 99 32 58 41];
cs = cumsum(sort(m))
cs =
-2 -15 -15 22 -8
5 3 -20 61 -2
20 55 -11 106 17
51 118 21 164 55
101 216 73 235 96
171 315 153 315 168
Now you easily identify at which element you cross the threshold cnstrn (thanks, #sevenless)!
out = sum(cs <= cnstrn)
out =
4 3 5 2 5
I'd add to Jonas's answer, that you can impose your constraint in a way that outputs a logical matrix then sum over the 1's and 0's of that matrix like so:
cstrn = 100
m= [
15 18 -5 22 19
50 98 -15 39 -8
70 -15 80 45 38
31 52 9 80 72
-2 63 52 71 6
7 99 32 58 41];
val_matrix = cumsum(sort(m))
logical_matrix = val_matrix<=cstrn
output = sum(logical_matrix)
Giving output:
cstrn =
100
val_matrix =
-2 -15 -15 22 -8
5 3 -20 61 -2
20 55 -11 106 17
51 118 21 164 55
101 216 73 235 96
171 315 153 315 168
logical_matrix =
1 1 1 1 1
1 1 1 1 1
1 1 1 0 1
1 0 1 0 1
0 0 1 0 1
0 0 0 0 0
output =
4 3 5 2 5
Here is a logic, on mobile so can't give a code.
Check this out. Go to a column, sort it ascending order, loop to sum, break when hits <=100. Get counter. Refer back to original column, get the indices of elements matching the elements you just summed up :-)