I wanted to use SelectKBest chi square for feature selection of categorical data.
df.shape yields (4000,150)
y.shape yields (4000,1)
On using the following code:
from sklearn.feature_selection import SelectKBest, chi2
df_new=SelectKBest(score_func=chi2,k=10).fit_transform(df,y)
It shows Attribute Error: 'SelectKBest' object has no attribute '_validate_data'
Any ideas what might be a solution to this?
try different sklean version if using 0.23.2
Related
Following the instructions of ipycitoscape I am not able to plot a graph using ipycitoscape.
according to: https://github.com/QuantStack/ipycytoscape/blob/master/examples/Test%20NetworkX%20methods.ipynb
this should work:
import networkx as nx
import ipycytoscape
G2 = nx.Graph()
G2.add_nodes_from([*'ABCDEF'])
G2.add_edges_from([('A','B'),('B','C'),('C','D'),('E','F')])
print(G2.nodes)
print(G2.edges)
cytoscapeobj = ipycytoscape.CytoscapeWidget()
cytoscapeobj.graph.add_graph_from_networkx(nx_graph)
G2 is a networkx graph example and it looks ok since print(G2) gives the networkx object back and G2.nodes and G2.edges can be printed.
The error:
ValueError: invalid literal for int() with base 10: 'A'
Why should a node be an integer?
More general what to do if the starting data point if a pandas dataframe with a million rows edges those being strings like ProcessA-ProcessB, processC-processD etc
Also having a look to the examples it is to be noted that the list of nodes is composed of a dictionary data for every node. that data including an "id" per node and also "Atribute". The surprise here is that the networkx Graph should have all those properties.
thanks
This problem was fixed. See attachment.
Please let me know if it's still happening. Feel free to open an issue: https://github.com/QuantStack/ipycytoscape/
I'm just playing around with ipycytoscape myself, so I could be way off-base, but, shouldn't the line be:
cytoscapeobj.graph.add_graph_from_networkx(G2) # your graph name goes here
Trying to generate a cytoscape object built on a graph that doesn't exist might trigger a ValueError because it can't find any nodes.
I'm porting matlab code to python and come across the code below. Looks like it creates a matrix but I'm not sure what the shape of the matrix would be. Can anybody help me understand what this code mean especially '...' and '].^2'?
somevarialbe = [var1...
var2...
var3].^2;
It is the item-wise operator and power each item to 2. In the other words, it is equivalent to the following code:
somevarialbe = [var1^2...
var2^2...
var3^2];
And ... means next line in the code. Hence, it is equivalent to the following code:
somevarialbe = [var1^2 var2^2 var3^2];
I've got the error of "Error using histc. First Input must be a real non-sparse numeric array" from the following codes.
N=10^4;
d=rand(1,N)>0.5;
symbols=unique(d);
probs = histc(d,symbols)./numel(d);
P/s: I try to generate using randsrc before. It did worked.But, I'm hoping not to use randsrc because it will affect my code later on. Any ideas on this would be appreciated.
Thanks.
Here is the working code
N=10^4;
d=double(rand(1,N)>0.5);
symbols=unique(d);
probs = histc(d,symbols)./numel(d);
I have written a macro for ImageJ/FIJI to deconvolve my confocal microscopy images and run the "3D Object Counter" plugin. The macro successfully runs all required commands and saves all required data in the specified places.
However, I have found that the 3D-OC autothreshold (as shown in the plugin dialog box) is to stringent resulting in objects being lost or divided.
To remedy this I would like to reduce the autothreshold by a predetermined function something similar to what was done here (from:How to get threshold value used by auto threshold Plugin) which resulted in this code:
setAutoThreshold();
getThreshold(lower,upper);
v=setThreshold(lower,upper*0.5);
run("3D Objects Counter", "threshold="v" slice=10 min.=400 max.=20971520 objects statistics summary");
The idea was to call the AutoThreshold values, modify them and set them to a variable. However when these lines are run the following error is returned:
Number or numeric function expected in line 3.
v=<setThreshold>(lower,upper*0.5);
And if the variable is inserted directly into the threshold key for run(3D-OC) the following msg is encountered:
Numeric value expected in run() function
Key:"threshold"
Value or variable name:"setThreshold(lower,upper*0.5"
Any suggestions or help on how to designate the 3D-OC threshold value as a variable as described would be greatly appreciated (as would any work arounds of course :) ).
Cheers
Edit: After testing Jan's response below (which works perfectly), it appears I need to call the threshold set by the 3D-OC plugin. Anyone know how to do this?
The getThreshold(lower, upper) function returns the lower and upper threshold levels in the provided variables. There is no need to assign any value to a new variable, and as you observed, setThreshold does not have any return value.
Instead, you can use the value(s) returned from getThreshold and use them as parameters in the run method (in the correct way, by string concatenation, see here):
setAutoThreshold();
getThreshold(lower, v);
run("3D Objects Counter", "threshold=" + v + " slice=10 min.=400 max.=20971520 objects statistics summary");
Alternatively, you can use &v in the second parameter to avoid string concatenation in the last line (see the documentation for the run() macro function):
run("3D Objects Counter", "threshold=&v slice=10 min.=400 max.=20971520 objects statistics summary");
You might have to use the lower instead of the upper threshold value, depending on whether you count bright or dark objects.
Im using iReport1.3.3 tool to create pdf and xls template ..
My problem is for the below expression,
($V{strloanNo}).divide($V{loanCalculation})
i need to divide both the variables but i am not getting expected result. it is displaying "null" value .
any idea guys?
$V{x}.divide( $V{y} )
This works for me.
It looks like your variables are Null.
Make sure to set the Initial Value Expression in the variable's properties.
I set both of mine to below.
new java.math.BigDecimal(10.0)
Guess you can try this out -
$V{strloanNo}.floatValue()/$V{loanCalculation}.floatValue()
As it was discussed
here, you can check this:
$F{Attribute_a}.divide($F{Attribute_b}, new MathContext(100))
If your division results in a non-terminating decimal then an exception is thrown. So you scale simply it to something reasonable and exception be gone.
$F{Attribute_a}.divide($F{Attribute_b})
and class type should be java.math.BigDecimal
if attribute b is zero, please put the condition