The following snippet won't compile.
Eigen::SparseMatrix<double> a(4, 5);
REDSVD::RedSVD svd(a, 2);

The precision of float is too low for some application.

What steps will reproduce the problem?
1.
>cat densa.txt
 1.5  0.0  2.5  2.5
 0.0  2.5  2.5  0.0
 1.5  0.0  2.5  1.0
 0.0  2.5  2.5  0.0
 0.0  2.5  2.5  0.0
2.
redsvd -i densa.txt -o densa -f dense -r 10
3.
>cat densa.U
-0.401793 +0.706597 -0.582481 +0.000000 
-0.486488 -0.308495 -0.038651 +0.000000 
-0.358540 +0.463912 +0.810083 +0.000000 
-0.486488 -0.308495 -0.038651 +0.000000 
-0.486488 -0.308495 -0.038651 +0.000000 
>cat densa.V
-0.165886 +0.472878 +0.409235 +0.000000 
-0.530701 -0.623149 -0.347478 +0.000000 
-0.807177 +0.164981 +0.334580 +0.000000 
-0.198253 +0.600711 -0.774494 +0.000000 


What is the expected output? What do you see instead?
First, I expected U to be 5 by 5. 
Tried same matrix in gnu octave, and the first 3 column match exactly, but the 
last one have values not zero:
octave-3.2.4:1> A=[1.5 0 2.5 2.5;0 2.5 2.5 0; 1.5 0 2.5 1.0; 0 2.5 2.5 0;0 2.5 
2.5 0]
A =

   1.50000   0.00000   2.50000   2.50000
   0.00000   2.50000   2.50000   0.00000
   1.50000   0.00000   2.50000   1.00000
   0.00000   2.50000   2.50000   0.00000
   0.00000   2.50000   2.50000   0.00000

octave-3.2.4:2> [u,s,v]=svd(A);
octave-3.2.4:3> u
u =

  -4.0179e-01   7.0660e-01   5.8248e-01   1.9052e-16  -3.8365e-20
  -4.8649e-01  -3.0849e-01   3.8651e-02   8.1650e-01  -1.2869e-16
  -3.5854e-01   4.6391e-01  -8.1008e-01  -3.1762e-17   3.8365e-20
  -4.8649e-01  -3.0849e-01   3.8651e-02  -4.0825e-01  -7.0711e-01
  -4.8649e-01  -3.0849e-01   3.8651e-02  -4.0825e-01   7.0711e-01

octave-3.2.4:4> v
v =

  -1.6589e-01   4.7288e-01  -4.0924e-01   7.6249e-01
  -5.3070e-01  -6.2315e-01   3.4748e-01   4.5750e-01
  -8.0718e-01   1.6498e-01  -3.3458e-01  -4.5750e-01
  -1.9825e-01   6.0071e-01   7.7449e-01   1.1102e-16

What version of the product are you using? On what operating system?
Ubuntu 12.04
redsvd 0.2.0


Please provide any additional information below.
I don't sure it is an issue, I didn't find any other information to let me know 
if this behavior is expected.

What steps will reproduce the problem?
1. ./RedSVD.exe -i ip.mat -o op -r 2 -m SymEigen -f sparse

2. cat ip.mat
0:1 3:0.5
1:1
2:1
0:0.5 3:1


What is the expected output? What do you see instead?
Expected: since the matrix is sparse and there are rows with just 1 non-zero 
value, I expect to see either eigen value of 1 or eigen vector with value at 
index 1 and index 2 to be 0 (if counting indices from 0). Something like
x_0
0
0
x_3

I see this:
cat op.evec
+0.463004 -0.795740
-0.735242 -0.368169
+0.411030 -0.080414
-0.275864 -0.474113

cat op.eval
+0.872274
+1.377271

What version of the product are you using? On what operating system?
I am compiling the code in visual studio 2013. The versions are:
1. redsvd 0.2.0
2. Eigen 3

Please provide any additional information below.
If I provide identity matrix, I get the correct eigen values and vectors. 
Adding 2 elements at some {i,j} and {j,i} location does not yield the correct 
eigen vectors. 

Am I missing something here ? Your help would be much appreciated. Thank you. 

What steps will reproduce the problem?
$ cat file1
 1.0  2.0  3.0  4.0  5.0
-2.0 -1.0  0.0  1.0  2.0
 1.0 -2.0  3.0 -5.0  7.0
$ redsvd -i file1 -o file1 -r 2 -f dense -m PCA && cat file1.*
compute PCA
read matrix from file1 ... -6.89179e-08 sec.
rows:   3
cols:   5
rank:   2
compute ... 3.49246e-09 sec.
write file1.pc
assertion "other.rows() == 1 || other.cols() == 1" failed: file 
"/usr/local/include/eigen3/Eigen/src/Core/DenseStorageBase.h", line 247, 
function: void Eigen::DenseStorageBase<Derived>::resizeLike(const 
Eigen::EigenBase<OtherDerived>&) [with OtherDerived = Eigen::Matrix<float, 
-0x000000001, -0x000000001, 0, -0x000000001, -0x000000001>, Derived = 
Eigen::Matrix<float, -0x000000001, 1, 0, -0x000000001, 1>]
Aborted (core dumped)


What is the expected output? What do you see instead?
計算結果が出力されてほしい

What version of the product are you using? On what operating system?
- Windows XP
- Cygwin 1.7
- redsvd 0.1.2
- eigen3 beta2

Please provide any additional information below.
writeMatrix(const string& fn, const REDSVD::RedPCA& A) 内のwriteVector_(const 
string& fn, const VectorXf& V)の呼び出しにおいて、MatrixXf 
RedPCA#scores()をVectorXfに変換しようとするところで落ちている
ようです。

How can I use redsvd with visual studio?

What steps will reproduce the problem?
$ cat file1
 1.0  2.0  3.0  4.0  5.0
-2.0 -1.0  0.0  1.0  2.0
 1.0 -2.0  3.0 -5.0  7.0
$ redsvd -i file1 -o file1 -r 2 -f dense -m SymEigen && cat file1.*
compute SymEigen
read matrix from file1 ... -4.07454e-09 sec.
rows:   3
cols:   5
rank:   2
compute ... assertion "lhs.cols() == rhs.rows() && "invalid matrix product" && 
"if you wanted a coeff-wise or a dot product use the respective explicit 
functions"" failed: file 
"/usr/local/include/eigen3/Eigen/src/Core/ProductBase.h", line 103, function: 
Eigen::ProductBase<Derived, Lhs, Rhs>::ProductBase(const Lhs&, const Rhs&) 
[with Derived = Eigen::GeneralProduct<Eigen::Transpose<Eigen::Matrix<float, 
-0x000000001, -0x000000001, 0, -0x000000001, -0x000000001> >, 
Eigen::Matrix<float, -0x000000001, -0x000000001, 0, -0x000000001, 
-0x000000001>, 5>, Lhs = Eigen::Transpose<Eigen::Matrix<float, -0x000000001, 
-0x000000001, 0, -0x000000001, -0x000000001> >, Rhs = Eigen::Matrix<float, 
-0x000000001, -0x000000001, 0, -0x000000001, -0x000000001>]
Aborted (core dumped)


What is the expected output? What do you see instead?
計算結果が出力されてほしい

What version of the product are you using? On what operating system?
- Windows XP
- Cygwin 1.7
- redsvd 0.1.2
- eigen3 beta2

Please provide any additional information below.

問題
cygwin/gcc3.4.4 
環境下でビルドしたredsvd0.1.2において、計算結果がnanになる

原因
 sampleTwoGaussian(float&,float&): redsvd.cppにおいて、

  float v1 = (float)(rand()) / ((float)RAND_MAX+1);
  float v2 = (float)(rand()) / ((float)RAND_MAX+1);
  float len = sqrt(-2.f * log(v1));

というコードがある。rand()の値域は0を含むが、v1に0が設定�
��れた場合lenがinfとなり以降の値がおかしくなる。

当該環境においては、srand()されていない場合、rand()を一回�
��に呼んだ時の初期値がかならず0となるため、常時計算結��
�がおかしくなることになる。

解決方法
rand()が0を返す場合を考慮する。
知識不足でパッチは書けませんでした。



以上よろしくお願いします。