Function printMatrixInFourQuadrants

quest/src/core/printer.cpp:700–779

void printMatrixInFourQuadrants(
    qcompmatr upperLeft, qcompmatr upperRight, 
    qcompmatr lowerLeft, qcompmatr lowerRight, 
    vector<string> leftColLabels,  vector<string> rightColLabels, // shown above the first row
    vector<string> upperRowLabels, vector<string> lowerRowLabels, // shown right of the last column
    string baseIndent, string indentPerRow, string verticalEllipsis
) {
    // this function prints a matrix which has been prior divided into one, two or four
    // quadrants, resulting from reporter truncation of the original matrix. It can be
    // used to print truncated (or non-truncated) non-square matrices, horizontal and
    // vertical vectors, diagonal matrices, and lists of scalars (e.g. Pauli coefficients)

    // the below preconditions are assumed but not enforced:
    // - it is valid for lowerLeft to be empty, implying upperLeft contains entire columns;
    //   in that scenario, lowerRight must also be empty
    // - it is valid for upperRight to be empty, implying upperLeft contains entire rows;
    //   in that scenario, lowerRight must also be empty
    // - it is valid for upperRight=lowerLeft=lowerRight to be empty, implying upperLeft
    //   contains the entire matrix
    // - it is valid for qcompmatr={} (empty), but it is INVALID to be {{}} (reported non-empty)
    // - it is INVALID for any qcompmatr to have an inconsistent number of columns across its rows
    // - it is INVALID for upperLeft and lowerLeft to differ in #columns, though #rows can vary;
    //   the same applies to upperRight and lowerRight
    // - it is INVALID for upperLeft and upperRight to differ in #rows, though #columns can vary;
    //   the same applies to lowerLeft and lowerRight
    // - it is INVALID for upperLeft to ever be empty
    // - it is valid for leftColLabels=rightColLabels to be empty, but otherwise...
    //   - leftColLabels must match the #cols in upperLeft (can contain empty strings)
    //   - rightColLabels must similarly match the #cols in upperRight
    // - it is valid for upperRight=lowerRight to be empty, while lowerLeft is not empty;
    //   this would be the case when printing a vector. Non-distributed vectors like this
    //   are fine, although distributed vectors should use a separate, bespoke routine since
    //   this function cannot display labeled ranks spanning vertically

    if (!comm_isRootNode())
        return;

    // prepare element strings
    stringmatr upperLeftStrings  = getMatrixOfQcompStrings(upperLeft);
    stringmatr upperRightStrings = getMatrixOfQcompStrings(upperRight);
    stringmatr lowerLeftStrings  = getMatrixOfQcompStrings(lowerLeft);
    stringmatr lowerRightStrings = getMatrixOfQcompStrings(lowerRight);

    // decide column widths
    vector<size_t> leftColWidths  = getMaxWidthOfColumns(upperLeftStrings,  lowerLeftStrings);
    vector<size_t> rightColWidths = getMaxWidthOfColumns(upperRightStrings, lowerRightStrings);

    // including consideration of column labels
    expandMaxWidthsAccordingToLabels(leftColWidths,  leftColLabels);
    expandMaxWidthsAccordingToLabels(rightColWidths, rightColLabels);

    // optionally print all column labels
    if (!leftColLabels.empty()) {
        cout << baseIndent;
        printRowInTwoQuadrants(leftColLabels, leftColWidths, rightColLabels, rightColWidths);
        cout << endl;
    }