I've following problem and don't know the terminology to describe it and hence search for possible solutions.
I have a pivot table (matrix), eg each row and column have a named header. there is a defined set for rows and columns. Now let's assume that 10 rows are "combined" meaning each column is summed up to create a new "pattern".
What I would like is a way to determine alternative row combinations that lead to the same or similar "combined" pattern.
1 1 1
5 5 5
"Combined"
6 6 6
alternate row combination:
2 2 2
4 4 4
Suggestions? How is this problem called?
http://en.wikipedia.org/wiki/System_of_linear_equations#Matrix_equation
I just have to transpose above matrix to get Matrix A
[code]
1 5
1 5
1 5
[/code]
combined matrix is a vector b:
[code]
6
6
6
[/code]
and x would be just a vector full of 1.
Related
Sorry for the beginner question.
I have an Outputs table:
ID
value
0
x
1
y
2
z
And an Inputs table that is linked to the Outputs through the outputsID:
ID
outputsID
name
0
0
A
1
1
B
2
1
C
3
2
B
4
2
C
Assuming that multiple outputs have at least one shared input (in this example outputID 1,3 and 2,4 are the same), is there a way to avoid the duplication of entries in my Inputs table (inputID 3 and 4)?
The 'normal' answer to your question is no. Rows 1 and 2 address output 1, and Rows 3 and 4 address output 2. They aren't duplicates and each reflect something distinct.
So if you are a beginner, I would say you shouldn't want to get rid of these rows.
That said, there are some more advanced techniques. For example, you could have the OutputsID column be an array with multiple values. This is harder, more complex, and non-standard.
I have a table with the following rows:
ID Description Number
1 Test 1 4
2 Test 2 3
3 Test 3 5
4 Test 5 6
How do I create my query so that if I want ID 3, it generates the following based on the Number column:
Count
1
2
3
4
5
Thanks. :)
It looks like your rows are already uniquley identified. You need to query the row with id 3, and then preform an operation with php to count out to the end of the number set. 5 in this case. You could use arrays, and just loop throjgh the array for each number as well.
What I Have:
I have a table where I have two basic columns on which the query is supposed to work
c1|c2
1 2
2 1
1 3
3 1
2 4
Now I want the result after the execution of the query is this
c1|c2
2 1
3 1
Notice
(3,1) was the last occurence of 1 and 3 no matter in which order they are as along as it is 1 and 3 and same is (2,1)
How can I achieve this where one value of the two columns is static for example in this case (1) is static and I want only those rows which has (1) in any of the two columns in their last occurrence.. Can any one help ?
I am working on NGSim Traffic data, having 18 columns and 1180598 rows in a text file. I want to smooth the position data, in the column 'Local Y'. I know there are built-in functions for data smoothing in R but none of them seem to match with the formula I am required to apply. The data in text file looks something like this:
Index VehicleID Total_Frames Local Y
1 2 5 35.381
2 2 5 39.381
3 2 5 43.381
4 2 5 47.38
5 2 5 51.381
6 4 8 504.828
7 4 8 508.325
8 4 8 512.841
9 4 8 516.338
10 4 8 520.854
11 4 8 524.592
12 4 8 528.682
13 4 8 532.901
14 5 7 39.154
15 5 7 43.153
16 5 7 47.154
17 5 7 51.154
18 5 7 55.153
19 5 7 59.154
20 5 7 63.154
The above data columns are just example taken out of original file. Here you can see 3 vehicles, with vehicle IDs = 2, 4 and 5 but in fact there are 2169 vehicles with different IDS. The column Total_Frames tell us how many times vehicle Id of each vehicle is repeated in the first column, for example in the table above, vehicle ID 2 is repeated 5 times, hence '5' in Total_Frames column. Following is the formula I am required to apply to remove data noise (smoothing) from column 'Local Y':
Smoothed Position Value = (1/(Summation of [EXP^-abs(i-k)/delta] from k=i-D to i+D)) * ( (Summation of (Local Y) *[EXP^-abs(i-k)/delta] from k=i-D to i+D))
where,
i = index #
delta = 5
D = 15
I have tried using the built-in functions, which I know of, but they don't smooth the data as required. My question is: Is there any built-in function in R which can do the data smoothing in the way of given formula or which could take this formula as an argument? I need to apply the formula to every value in Local Y which has 15 values before and 15 values after them (i-D and i+D) for same vehicle Id. Can anyone give me any idea how to approach the problem? Thanks in advance.
You can place your formula in a function and then use the apply function of R to apply it to the elements in your "Local Y" column of the dataframe
I have a column in table A. the column name is Sequence number. The Structure of table A is numbers from 1,2,3,4.....3600.
Now on the basis of table A. I want the below output from the SQL select query for SQL server 2008.
seq no dynamic col
1 1
2 1
3 1
4 1
5 1
6 2
7 2
8 2
9 2
10 2
11 2
12 3
13 3
My Second column is getting generated at the run time.
And the business logic is that, if the seq number mod 6 = 0 then increment the value of dynamic column.
Thanks in advance
Try this:
select seqno, (seqno/6) +1 dynamiccol
from t
Fiddle Demo
Take this as pseudo code because I'm not familiar with SQL Server specifically, but it should give you somewhere to go.
SELECT
seq_no,
ROUNDDOWN(seq_no/6)+1 AS dynamic_col
FROM
my_table