In the ssgui you are presented with four primary panels.
Selection Criteria panel:
This is used for rule-based selections of matrix subsets. A matrix must
satisfy all properties in this panel to be selected. With the default settings
(available when the ssgui starts or after clicking Reset criteria) all
matrices fit the criteria. However, no matrix is selected until you press the
Select button or select them individually in the table by clicking the
checkbox in the select column.
The selection criteria are based on the matrices properties described in
the matrix table (described below). To select matrices from one or more groups
and/or "kinds," click on the choices in the "group" and/or "kind" lists.
Shift-click the list to select a range of groups or kinds, and control-click
the list to add a single item to your highlighted choices. To clear your
choices, click the Reset criteria button, described below.
When you select/deselect matrices, the boxes to the left of each matrix in
the Table of Matrices get checked/unchecked. You still see all the matrices
in the list, because you can then modify your selection by checking/unchecking
matrices one at a time in the Table itself.
At the bottom of the Selection Criteria panel is a row of buttons:
- Select: Click this to add matrices to your selection
that fit the criteria. No matrix is removed from any prior selection.
For example, to select all square matrices with fewer than 1000 rows,
plus all complex matrices, do the following. First enter 1000 in the
top-right text field, click the square radio button, and then
click Select. Then click Reset criteria. Next, click
complex and then Select.
- Deselect: Click this to remove matrices from your selection
that fit the criteria. In general, if you want matrices that meet some
criteria (a) but not (b), then set the controls for (a) and click
Select. Next, click Reset criteria, set the criteria
(b), and click Deselect. For example, to select all square
matrices with fewer than 1000 rows that are not complex, you could just
do this with a single click of Select (click square,
real, and enter 1000 in the top-right text field, then click
Select). Alternatively, you could click square and enter
1000 as the upper bound on the number of rows and click Select
then Reset criteria, select complex, and click
Deselect.
- Reset criteria: This has no effect on your selection. It
simply resets the criteria to the default (all matrices). Thus, to
select all matrices, click Reset criteria and then
Select. To deselect all matrices, click Reset criteria
and then Deselect.
- Clear selections: This has no effect on your selection
criteria. It simply clears all selections, deselecting all matrices by
unchecking the select column in the table. This is useful if
you have a complex selection criteria and don't want to lose it by
clicking Reset criteria, but you wish to clear all your
selections anyway.
- Help: this button brings up the text you're reading.
Matrix icon panel:
To the right of the Selection Criteria panel is an icon of the most recent
matrix highlighted, downloaded, or in the process of being downloaded.
Table of matrices:
This is a list of all the matrices in the collection. You can click on any
column header to sort the table by that column. Clicking a row (to the right
of the select column) will highlight that row. You can highlight a range of
rows by shift-clicking another row. Control-click will add individual rows.
Next, right-clicking in the table will pull up a pop-up menu allowing you to
select or deselect the highlighted matrices and to export your selection to a
file. You can export a list of your selected matrices to a comma-separarted
file (*.csv) or to a MATLAB (*.m) file. When you highlight a matrix, its icon
is displayed.
The table contains the following columns (you can also hover your mouse
over each column header for a short description):
- select: whether or not you have selected the matrix.
You can click on the check boxes in this column to modify your
selection on a matrix-by-matrix basis. This is the only column in
the table that you can edit.
- mat: this box is checked if you have downloaded the matrix
in its MATLAB format. The location of the HB/west0067.mat file
will be ssget/mat/HB/west0067.mat, for example.
- MM: this is checked if you have already downloaded
the matrix in its Matrix Market format.
- RB: this is checked if you have already downloaded
the matrix in its Rutherford/Boeing format.
- id: the matrix id, in the range 1 to the number of
matrices in the collection. When the ssgui starts,
the table is sorted in this order.
- Group: the group the matrix belongs to.
- Name: the (short) name of the matrix. The full name of
a matrix is Group/Name.
- # rows: the number of rows of the matrix.
- # cols: the number of columns of the matrix.
- # nonzeros: the number of nonzeros in the matrix.
- real: this box is checked if the matrix is real.
It is complex otherwise.
Note that real matrices include any matrix that is not
complex. In particular, integer and binary matrices are
considered real in this search criterion.
- binary: this box is checked if the matrix is binary.
It is non-binary otherwise (there are no binary complex matrices,
so any matrix that is binary is also marked as real).
- 2D/3D: this box is checked if the matrix comes
from a discretization of a 2D or 3D geometry.
- posdef: this box is checked if the matrix is
symmetric and positive definite.
- psym: the symmetry of the nonzero pattern of the
matrix A (including the binary Zeros matrix as well). Let
S = pattern(pattern(A)+Zeros) where pattern(A) is a
binary matrix with entries equal to 1 where A(i,j) is
nonzero, and zero elsewhere. The psym metric is zero if the
pattern of S is completely unsymmetric, and 1.0 if the
pattern is exactly symmetric. Let pmatched be the number of
off-diagonal entries S(i,j) for which S(i,j)=S(j,i)
and let pnzoffdiag be the total number off-diagonal entries
in S. Then psym is the ratio
pmatched/pnzoffdiag.
- nsym: the symmetry of the numerical values of the
matrix. This property ignores the Zeros matrix. It is
equal to 0 for a perfectly unsymmetric matrix, and 1.0 for a
symmetric matrix. Let matched be the number of nonzero
off-diagonal entries A(i,j) for which A(i,j)=A(j,i)
and let nzoffdiag be the total number off-diagonal nonzero
entries in A. Then psym is the ratio
matched/nzoffdiag.
- kind: the problem domain. Note that this is typically
related to the problem group, since many matrix authors submit
matrices to the collection that arise from a single problem domain.
Some group have problems from many domains, however.
Download panel:
This panel controls the downloading of matrices, with
three check boxes, three buttons, and informational items:
- Download: click this to begin the download of the
selected matrices. Matrices that are already downloaded are skipped
(thus, if one of your matrix files happens to get corrupted, simply
remove the file and restart the ssgui). Matrices are downloaded into
the mat, MM, and RB folders inside the ssget
folder, in the same order as they appear in the table view. For
example, if you click on the # nonzeros column heading prior to
clicking Download, your selected matrices will be downloaded in
order of increasing number of nonzero entries. If you hover your mouse
over the download button, a tool tip will tell you what it will do.
- MATLAB (mat) format: click this to download the selected
matrices in MATLAB *.mat format.
- Matrix Market (MM) format: click this to download the selected
matrices in Matrix Market format.
- Rutherford/Boeing (RB) format: click this to download the
selected matrices in Rutherford/Boeing format.
- Matrices selected: gives a running total of the number of
matrices selected in the table.
- Cancel: click to cancel the current download, deleting the
matrix currently being downloaded. Matrices already fully downloaded
are never deleted by the ssgui program.
- Overall progress: this progress bar advances after each
matrix is downloaded.
- Current file: this progress bar advances as the current
matrix is downloaded. The icon and name of the matrix currently
being downloaded is shown in the icon panel.
The contents of the mat, files,
MM, and RB
folders ("directories" for Unix users), and the ssstats.txt file itself,
maybe be deleted at will when the program is not running. They will be
recreated when the program restarts. If you delete the files
directory, for example, matrix icons are redownloaded, which makes for a
fun slide show. Sit back and watch.