I can make it work like this:
book = xlrd.open_workbook(Path+'infile')
sheet = book.sheet_by_index(0)
A, B, C, D = ([] for i in range (4))
A = sheet.col_values(0)
B = sheet.col_values(1)
C = sheet.col_values(2)
D = sheet.col_values(3)
but what I want is to make it work like this:
dyn_var_list = [A, B, C, D]
assert(len(sheet.row_values(0))==len(dyn_var_list))
for index, col in enumerate(sheet.row_values(0)):
dyn_var_list[index].append(col)
however, so far I can only get one value in my lists, using the code above, which is due to the usage of "(0)" after the row_values I guess, but I don't know how to resolve this as of yet.
Try
for c in range(sheet.ncols):
for r in range(sheet.nrows):
dyn_var_list[c].append(sheet.cell(r,c).value)
Here sheet.nrows gives you the number of rows in the sheet.
Related
I want Scalafmt to accept this kind of formatting:
val result = longMethodName(
a, b, c, d)
But currently it gets turned into:
val result = longMethodName(
a,
b,
c,
d)
When the parameters are short the first form is much more pleasing. Is there an option to allow it?
I am trying to minimize the function || Cx - d ||_2^2 with constraints Ax <= b. Some information about their sizes is as such:
* C is a (138, 22) matrix
* d is a (138,) vector
* A is a (138, 22) matrix
* b is a (138, ) vector of zeros
So I have 138 equation and 22 free variables that I'd like to optimize. I am currently coding this in Python and am using the transpose C.T*C to form a square matrix. The entire code looks like this
C = matrix(np.matmul(w, b).astype('double'))
b = matrix(np.matmul(w, np.log(dwi)).astype('double').reshape(-1))
P = C.T * C
q = -C.T * b
G = matrix(-constraints)
h = matrix(np.zeros(G.size[0]))
dt = np.array(solvers.qp(P, q, G, h, dims)['x']).reshape(-1)
where np.matmul(w, b) is C and np.matmul(w, np.log(dwi)) is d. Variables P and q are C and b multiplied by the transpose C.T to form a square multiplier matrix and constant vector, respectively. This works perfectly and I can find a solution.
I'd like to know whether this my approach makes mathematical sense. From my limited knowledge of linear algebra I know that a square matrix produces a unique solution, but is there is a way to run the same this to produce an overdetermined solution? I tried this but solver.qp said input Q needs to be a square matrix.
We can also parse in a dims argument to solver.qp, which I tried, but received the error:
use of function valued P, G, A requires a user-provided kktsolver.
How do I correctly setup dims?
Thanks a lot for any help. I'll try to clarify any questions as best as I can.
I wonder whether it's possible to give a name to the output of a certain expression to retrieve it from the graph at another part of the code.
For example
def A(a, b):
c = a + b
d = d * a
return d
For debug purposes it would be nice if I could pull out c at another position without returning it through the entire function hierarchy.
Any ideas?
Thanks in advance!
I'm assuming a and b are tensors.
Either you give a name to c using tf.identity
def A(a, b):
c = a + b
c = tf.identity(c, name = "c")
d = d * a
return d
Either you use the tf.add operation instead of +:
def A(a, b):
tf.add(a, b, name = "c")
d = d * a
return d
Either way, you get retrieve c with tf.get_variable('c:0') (You might need to precise the scope if any.)
I would like to generate combinations in pig with the help of FOREACH. Is there any possible way to do this ?
My Input:
A
B
C
Objective:
A,B
A,C
B,C
Here's the sample which I have tried. This sample shows " Syntax error, unexpected symbol at or near '$0' ".
A = load '/test';
B = foreach A generate $0;
Combination = Cross A, B;
Combination_Filter = foreach Combination generate $0 < $1;
Please help me in resolving this. Thanks in Advance
Can you try the below options?
input:
A
B
C
Option1:
A = LOAD 'input' AS(f1:chararray);
B = LOAD 'input' AS(f2:chararray);
C = CROSS A,B;
D = FILTER C BY A::f1 < B::f2;
DUMP D;
Option2:
A = LOAD 'input' AS (f1:chararray);
B = FOREACH A GENERATE f1 AS (f2:chararray);
C = CROSS A,B;
D = FILTER C BY A::f1 < B::f2;
DUMP D;
Output:
(A,B)
(A,C)
(B,C)
It is not possible to do that using only foreach, the only way to achieve something like that would be with Sivasakthi's answer, or using a custom UDF. You can put all the registers in a bag with a group all, and then run the UDF.
The UDF is in this other question: How to turn (A, B, C) into (AB, AC, BC) with Pig?
The code would be something like:
A = load '/test';
A_grouped = group A all;
A_combinations = foreach A_grouped generate CombinationsUDF(A);
In most languages, if you want to swap two variables, it's something like:
var c = b
b = a
a = c
Yes, you can do fancy hacks with XOR if you like but it's generally 3 lines of code for a single operation. Are there any languages that have swapping variables as a primitive in the language?
Lua, Python, Ruby and more support this notation:
a, b = b, a
And javascript sure needs no temporary variable either ;)
a = -(b = (a += b) - b) + a;
For more examples on how to swap variables (in 86 languages), see: http://rosettacode.org/wiki/Generic_swap
In most dynamic languages you can do something like this to swap:
a, b = b, a
Now a have the value of b, and b has the value of a. I am not sure if this is what you meant or not.