A *Solver Section* is used to solve systems of equations.

To use a solver section, type in equations with the variable names you wish to solve for. These must be unused as value names in the frame. When there is enough information to solve the system of equations, the results will appear at the bottom of the section.

##### Insert a solver section:

- While inside a report or multiline cell, select the insert tool.
- Select
*Solver Section*. - Click OK.

##### Methodology

For a linear system of equations, solver sections solve the system directly with matrix operations. Units are determined directly based on the equations.

For a non-linear system, Blockpad attempts to solve the system through multi-variable Newton-Raphson iteration. By default, the initial guess for each variable is 0. Alternative initial guesses may be set through the Initial Guess Property. To control result units for a non-linear system, set the the initial guess to a number with the desired unit.

If the solver is unable to converge on a solution, each variable is set to an error state. You can view the iteration log of a solver section in the formula browser using the show in formula browser tool.

##### Examples

Here a free body diagram is solved with the solver section and depicted using the Blockpad drawing tool.

This example uses a solver section to find the friction factor for a head loss calculation. The initial guess for f is set to 0.01.

Here the solver section is used to find the length in a buckling equation.

##### Notes:

- Because capture variables is set to no by default for solver sections, you can reference the results in formulas using only the variable names.
- You can conditionally hide a section using the hide property.