gidden

$S = -k \sum_{n \in N} p_n \ln p_n$

gidden

# given an array of data called x:
import numpy as np
sum_of_squares = np.sum(x ** 2)

# if your data is in a list, not a numpy array:
sum_of_squares = np.sum(np.array(x) ** 2)

gidden

Copyright (c) 2015, Matthew Gidden All rights reserved.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
3. Neither the name of the copyright holder nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.

gidden

$ go get github.com/rwcarlsen/cyan/cmd/cyan
package github.com/rwcarlsen/cyan/cmd/cyan
	imports runtime: C source files not allowed when not using cgo: atomic_amd64x.c defs.c float.c heapdump.c lfstack.c malloc.c mcache.c mcentral.c mem_linux.c mfixalloc.c mgc0.c mheap.c msize.c os_linux.c panic.c parfor.c proc.c runtime.c signal.c signal_amd64x.c signal_unix.c stack.c string.c sys_x86.c vdso_linux_amd64.c
import cycle not allowed
package github.com/rwcarlsen/cyan/cmd/cyan
	imports github.com/rwcarlsen/cyan/Godeps/_workspace/src/code.google.com/p/go-uuid/uuid
	imports net
	imports runtime/cgo
	imports runtime/cgo

gidden

$ docker build -t cyclus/site .
Sending build context to Docker daemon   111 MB
Sending build context to Docker daemon 
Step 0 : FROM cyclus/cycamore
 ---> c9e8370a5885
Step 1 : RUN apt-get -y --force-yes update
 ---> Using cache
 ---> 510880db9298
Step 2 : RUN apt-get install -y wget
 ---> Using cache

gidden

Setup

This is a network flow representation within a simulation. Binary variables represent real flows and linear variables represent "fake" slack flows (to guarantee feasibility). Everything is automatically generated based on the simulation context, so in this very simple example there are constraints that appear which are superfluous, e.g., 0 <= y <= 1 is superfluous with y \in {0, 1}. There are 20 binary variables in two categories (supplier 1, supplier 2) and 20 linear variables.

Issue

There is a constraint of the form \sum a_1 y + \sum a_2 y <= 10.01. Values of a_1 and a_2 are chosen such that 10 a_1 + 8 a_2 == 10.004 < 10.01 and 10 a_1 + 9 a_2 == 10.349 > 10.01. However, the solution reported by CBC is setting all supplier 1 variables to 1 and 9 supplier 2 variables to 1, which violates the constraint. I would expect only 8 supplier 2 variables to be set to 1.

gidden

H/W path       Device     Class          Description
====================================================
                          system         MacBookAir6,2 (System SKU#)
/0                        bus            Mac-7DF21CB3ED6977E5
/0/0                      processor      Intel(R) Core(TM) i5-4260U CPU @ 1.40GHz
/0/0/2                    memory         64KiB L1 cache
/0/0/3                    memory         512KiB L2 cache
/0/0/4                    memory         3MiB L3 cache
/0/1                      memory         64KiB L1 cache
/0/5                      memory         4GiB System Memory

gidden

H/W path       Device     Class          Description
====================================================
                          system         MacBookAir6,2 (System SKU#)
/0                        bus            Mac-7DF21CB3ED6977E5
/0/0                      processor      Intel(R) Core(TM) i5-4260U CPU @ 1.40GHz
/0/0/2                    memory         64KiB L1 cache
/0/0/3                    memory         512KiB L2 cache
/0/0/4                    memory         3MiB L3 cache
/0/1                      memory         64KiB L1 cache
/0/5                      memory         4GiB System Memory

gidden

H/W path        Device      Class          Description
======================================================
                            system         OptiPlex 9010 ()
/0                          bus            0W2F8G
/0/0                        memory         64KiB BIOS
/0/5c                       processor      Intel(R) Core(TM) i7-3770 CPU @ 3.40GHz
/0/5c/38                    memory         256KiB L1 cache
/0/5c/39                    memory         1MiB L2 cache
/0/5c/3a                    memory         8MiB L3 cache
/0/3b                       memory         16GiB System Memory

gidden

Time Quantity 
0    0        
1    99000    
2    99000    
3    198000   
4    198000   
5    297000   
6    297000   
7    396000   
8    396000