---
name: "SbDPMatrix"
section: "3"
platform: "linux"
package: "coin"
version: "1:4.0.10-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/SbDPMatrix"
---

# SbDPMatrix(3)

The SbDPMatrix class is a 4x4 dimensional representation of a double-precision matrix.

## NAME

SbDPMatrix - The **SbDPMatrix** class is a 4x4 dimensional representation of a double-precision matrix.

## SYNOPSIS

\#include \<Inventor/SbDPMatrix.h\>

### Public Member Functions

**SbDPMatrix** (void)\
 **SbDPMatrix** (const double a11, const double a12, const double a13, const double a14, const double a21, const double a22, const double a23, const double a24, const double a31, const double a32, const double a33, const double a34, const double a41, const double a42, const double a43, const double a44)\
 **SbDPMatrix** (const SbDPMat &matrix)\
 **SbDPMatrix** (const SbDPMat \*matrix)\
 **SbDPMatrix** (const **SbMatrix** &matrix)\
 **~SbDPMatrix** (void)\
 void **setValue** (const SbDPMat &m)\
 void **setValue** (const **SbMatrix** &m)\
 void **setValue** (const double \*pMat)\
 const SbDPMat & **getValue** (void) const\
 void **makeIdentity** (void)\
 void **setRotate** (const **SbDPRotation** &q)\
 **SbDPMatrix** **inverse** (void) const\
 double **det3** (int r1, int r2, int r3, int c1, int c2, int c3) const\
 double **det3** (void) const\
 double **det4** (void) const\
 SbBool **equals** (const **SbDPMatrix** &m, double tolerance) const\
 void **getValue** (SbDPMat &m) const\
 void **setScale** (const double s)\
 void **setScale** (const **SbVec3d** &s)\
 void **setTranslate** (const **SbVec3d** &t)\
 void **setTransform** (const **SbVec3d** &t, const **SbDPRotation** &r, const **SbVec3d** &s)\
 void **setTransform** (const **SbVec3d** &t, const **SbDPRotation** &r, const **SbVec3d** &s, const **SbDPRotation** &so)\
 void **setTransform** (const **SbVec3d** &translation, const **SbDPRotation** &rotation, const **SbVec3d** &scaleFactor, const **SbDPRotation** &scaleOrientation, const **SbVec3d** &center)\
 void **getTransform** (**SbVec3d** &t, **SbDPRotation** &r, **SbVec3d** &s, **SbDPRotation** &so) const\
 void **getTransform** (**SbVec3d** &translation, **SbDPRotation** &rotation, **SbVec3d** &scaleFactor, **SbDPRotation** &scaleOrientation, const **SbVec3d** &center) const\
 SbBool **factor** (**SbDPMatrix** &r, **SbVec3d** &s, **SbDPMatrix** &u, **SbVec3d** &t, **SbDPMatrix** &proj)\
 SbBool **LUDecomposition** (int index\[4\], double &d)\
 void **LUBackSubstitution** (int index\[4\], double b\[4\]) const\
 **SbDPMatrix** **transpose** (void) const\
 **SbDPMatrix** & **multRight** (const **SbDPMatrix** &m)\
 **SbDPMatrix** & **multLeft** (const **SbDPMatrix** &m)\
 void **multMatrixVec** (const **SbVec3d** &src, **SbVec3d** &dst) const\
 void **multVecMatrix** (const **SbVec3d** &src, **SbVec3d** &dst) const\
 void **multDirMatrix** (const **SbVec3d** &src, **SbVec3d** &dst) const\
 void **multLineMatrix** (const **SbDPLine** &src, **SbDPLine** &dst) const\
 void **multVecMatrix** (const **SbVec4d** &src, **SbVec4d** &dst) const\
 void **print** (FILE \*fp) const\
 **operator double \*** (void)\
 **operator SbDPMat &** (void)\
 double \* **operator\[\]** (int i)\
 const double \* **operator\[\]** (int i) const\
 **SbDPMatrix** & **operator=** (const SbDPMat &m)\
 **SbDPMatrix** & **operator=** (const **SbDPMatrix** &m)\
 **SbDPMatrix** & **operator=** (const **SbDPRotation** &q)\
 **SbDPMatrix** & **operator\*=** (const **SbDPMatrix** &m)\

### Static Public Member Functions

static **SbDPMatrix** **identity** (void)\

## Detailed Description

The **SbDPMatrix** class is a 4x4 dimensional representation of a double-precision matrix.

This class is like the **SbMatrix** class, but uses double-precision floating-point values for its elements. For more class documentation, see **SbMatrix**.

**Since**

Coin 2.0.

## Constructor & Destructor Documentation

### SbDPMatrix::SbDPMatrix (void )

The default constructor does nothing. The matrix will be uninitialized.

### SbDPMatrix::SbDPMatrix (const double a11, const double a12, const double a13, const double a14, const double a21, const double a22, const double a23, const double a24, const double a31, const double a32, const double a33, const double a34, const double a41, const double a42, const double a43, const double a44)

Constructs a matrix instance with the given initial elements.

### SbDPMatrix::SbDPMatrix (const SbDPMat & matrixref)

Constructs a matrix instance with the initial elements from the *matrix* argument.

### SbDPMatrix::SbDPMatrix (const SbDPMat \* matrixptr)

This constructor is courtesy of the Microsoft Visual C++ compiler.

### SbDPMatrix::SbDPMatrix (const SbMatrix & matrixref)

This constructor converts a single-precision matrix to a double-precision matrix.

### SbDPMatrix::~SbDPMatrix (void )

Default destructor does nothing.

## Member Function Documentation

### void SbDPMatrix::setValue (const SbDPMat & m)

Copies the elements from *m* into the matrix.

**See also**

**getValue()**.

### void SbDPMatrix::setValue (const SbMatrix & m)

Copies the elements from *m* into the matrix.

**See also**

**getValue()**.

### void SbDPMatrix::setValue (const double \* m)

Copies the elements from *m* into the matrix.

**See also**

**getValue()**.

### const SbDPMat & SbDPMatrix::getValue (void ) const

Returns a pointer to the 2 dimensional double array with the matrix elements.

**See also**

**setValue()**.

### void SbDPMatrix::makeIdentity (void )

Set the matrix to be the identity matrix.

**See also**

**identity()**.

### void SbDPMatrix::setRotate (const SbDPRotation & q)

Set matrix to be a rotation matrix with the given rotation.

**See also**

**setTranslate()**, **setScale()**.

### SbDPMatrix SbDPMatrix::inverse (void ) const

Return a new matrix which is the inverse matrix of this.

The user is responsible for checking that this is a valid operation to execute, by first making sure that the result of **SbDPMatrix::det4()** is not equal to zero.

### double SbDPMatrix::det3 (int r1, int r2, int r3, int c1, int c2, int c3) const

Returns the determinant of the 3x3 submatrix specified by the row and column indices.

### double SbDPMatrix::det3 (void ) const

Returns the determinant of the upper left 3x3 submatrix.

### double SbDPMatrix::det4 (void ) const

Returns the determinant of the matrix.

### SbBool SbDPMatrix::equals (const SbDPMatrix & m, double tolerance) const

Check if the *m* matrix is equal to this one, within the given tolerance value. The tolerance value is applied in the comparison on a component by component basis.

### void SbDPMatrix::getValue (SbDPMat & m) const

Return matrix components in the SbDPMat structure.

**See also**

**setValue()**.

### SbDPMatrix SbDPMatrix::identity (void ) \[static\]

Return the identity matrix.

**See also**

**makeIdentity()**.

### void SbDPMatrix::setScale (const double s)

Set matrix to be a pure scaling matrix. Scale factors are specified by *s*.

**See also**

**setRotate()**, **setTranslate()**.

### void SbDPMatrix::setScale (const SbVec3d & s)

Set matrix to be a pure scaling matrix. Scale factors in x, y and z is specified by the *s* vector.

**See also**

**setRotate()**, **setTranslate()**.

### void SbDPMatrix::setTranslate (const SbVec3d & t)

Make this matrix into a pure translation matrix (no scale or rotation components) with the given vector *t* as the translation.

**See also**

**setRotate()**, **setScale()**.

### void SbDPMatrix::setTransform (const SbVec3d & t, const SbDPRotation & r, const SbVec3d & s)

Set translation, rotation and scaling all at once. The resulting matrix gets calculated like this:

```
M = S * R * T
```

where *S*, *R* and *T* is scaling, rotation and translation matrices.

**See also**

**setTranslate()**, **setRotate()**, **setScale()** and **getTransform()**.

### void SbDPMatrix::setTransform (const SbVec3d & t, const SbDPRotation & r, const SbVec3d & s, const SbDPRotation & so)

Set translation, rotation and scaling all at once with a specified scale orientation. The resulting matrix gets calculated like this:

```
M = Ro^-1 * S * Ro * R * T
```

where *Ro* is the scale orientation, and *S*, *R* and *T* is scaling, rotation and translation.

**See also**

**setTranslate()**, **setRotate()**, **setScale()** and **getTransform()**.

### void SbDPMatrix::setTransform (const SbVec3d & translation, const SbDPRotation & rotation, const SbVec3d & scaleFactor, const SbDPRotation & scaleOrientation, const SbVec3d & center)

Set translation, rotation and scaling all at once with a specified scale orientation and center point. The resulting matrix gets calculated like this:

```
M = -Tc * Ro^-1 * S * Ro * R * T * Tc
```

where *Tc* is the center point, *Ro* the scale orientation, *S*, *R* and *T* is scaling, rotation and translation.

**See also**

**setTranslate()**, **setRotate()**, **setScale()** and **getTransform()**.

### void SbDPMatrix::getTransform (SbVec3d & t, SbDPRotation & r, SbVec3d & s, SbDPRotation & so) const

Factor the matrix back into its translation, rotation, scale and scale orientation components.

**See also**

**factor()**

### void SbDPMatrix::getTransform (SbVec3d & translation, SbDPRotation & rotation, SbVec3d & scaleFactor, SbDPRotation & scaleOrientation, const SbVec3d & center) const

Factor the matrix back into its *translation*, *rotation*, *scaleFactor* and *scaleorientation* components. Will eliminate the *center* variable from the matrix.

**See also**

**factor()**

### SbBool SbDPMatrix::factor (SbDPMatrix & r, SbVec3d & s, SbDPMatrix & u, SbVec3d & t, SbDPMatrix & proj)

This function is not implemented in Coin.

**See also**

**getTransform()**

### SbBool SbDPMatrix::LUDecomposition (int index\[4\], double & d)

This function produces a permuted LU decomposition of the matrix. It uses the common single-row-pivoting strategy.

*FALSE* is returned if the matrix is singular, which it never is, because of small adjustment values inserted if a singularity is found (as Open Inventor does too).

The parity argument is always set to 1.0 or -1.0. Don't really know what it's for, so it's not checked for correctness.

The index\[\] argument returns the permutation that was done on the matrix to LU-decompose it. index\[i\] is the row that row i was swapped with at step i in the decomposition, so index\[\] is not the actual permutation of the row indexes!

BUGS: The function does not produce results that are numerically identical with those produced by Open Inventor for the same matrices, because the pivoting strategy in OI was never fully understood.

**See also**

**SbDPMatrix::LUBackSubstitution**

### void SbDPMatrix::LUBackSubstitution (int index\[4\], double b\[4\]) const

This function does a solve on the "Ax = b" system, given that the matrix is LU-decomposed in advance. First, a forward substitution is done on the lower system (Ly = b), and then a backwards substitution is done on the upper triangular system (Ux = y).

The index\[\] argument is the one returned from **SbDPMatrix::LUDecomposition()**, so see that function for an explanation.

The b\[\] argument must contain the b vector in "Ax = b" when calling the function. After the function has solved the system, the b\[\] vector contains the x vector.

BUGS: As is done by Open Inventor, unsolvable x values will not return NaN but 0.

### SbDPMatrix SbDPMatrix::transpose (void ) const

Returns the transpose of this matrix.

### SbDPMatrix & SbDPMatrix::multRight (const SbDPMatrix & m)

Let this matrix be right-multiplied by *m*. Returns reference to self.

**See also**

**multLeft()**

### SbDPMatrix & SbDPMatrix::multLeft (const SbDPMatrix & m)

Let this matrix be left-multiplied by *m*. Returns reference to self.

**See also**

**multRight()**

### void SbDPMatrix::multMatrixVec (const SbVec3d & src, SbVec3d & dst) const

Multiply *src* vector with this matrix and return the result in *dst*. Multiplication is done with the vector on the right side of the expression, i.e. dst = M \* src.

**See also**

**multVecMatrix()**, **multDirMatrix()** and **multLineMatrix()**.

### void SbDPMatrix::multVecMatrix (const SbVec3d & src, SbVec3d & dst) const

Multiply *src* vector with this matrix and return the result in *dst*. Multiplication is done with the vector on the left side of the expression, i.e. dst = src \* M.

It is safe to let *src* and *dst* be the same **SbVec3d** instance.

**See also**

**multMatrixVec()**, **multDirMatrix()** and **multLineMatrix()**.

### void SbDPMatrix::multDirMatrix (const SbVec3d & src, SbVec3d & dst) const

Multiplies *src* by the matrix. *src* is assumed to be a direction vector, and the translation components of the matrix are therefore ignored.

Multiplication is done with the vector on the left side of the expression, i.e. dst = src \* M.

**See also**

**multVecMatrix()**, **multMatrixVec()** and **multLineMatrix()**.

### void SbDPMatrix::multLineMatrix (const SbDPLine & src, SbDPLine & dst) const

Multiplies line point with the full matrix and multiplies the line direction with the matrix without the translation components.

**See also**

**multVecMatrix()**, **multMatrixVec()** and **multDirMatrix()**.

### void SbDPMatrix::multVecMatrix (const SbVec4d & src, SbVec4d & dst) const

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

### void SbDPMatrix::print (FILE \* fp) const

Write out the matrix contents to the given file.

### SbDPMatrix::operator double \* (void )

Return pointer to the matrix' 4x4 double array.

### SbDPMatrix::operator SbDPMat & (void )

Return pointer to the matrix' 4x4 double array.

### double \* SbDPMatrix::operator\[\] (int i)

Returns pointer to the 4 element array representing a matrix row. *i* should be within \[0, 3\].

**See also**

**getValue()**, **setValue()**.

### const double \* SbDPMatrix::operator\[\] (int i) const

Returns pointer to the 4 element array representing a matrix row. *i* should be within \[0, 3\].

**See also**

**getValue()**, **setValue()**.

### SbDPMatrix & SbDPMatrix::operator= (const SbDPMat & m)

Assignment operator. Copies the elements from *m* to the matrix.

### SbDPMatrix & SbDPMatrix::operator= (const SbDPMatrix & m)

Assignment operator. Copies the elements from *m* to the matrix.

### SbDPMatrix & SbDPMatrix::operator= (const SbDPRotation & q)

Set matrix to be a rotation matrix with the given rotation.

**See also**

**setRotate()**.

### SbDPMatrix & SbDPMatrix::operator\*= (const SbDPMatrix & m)

Right-multiply with the *m* matrix.

**See also**

**multRight()**.

## Author

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