# Calculate with graphs

Learn how Boulder Opal uses computational graphs to represent systems and perform operations

### Get an introduction to graphs in Boulder Opal

An overview of how Boulder Opal uses computational graphs to represent systems and perform operations

### Implement time-dependent functions in Boulder Opal

An overview of how time-dependent functions are represented in Boulder Opal graphs

### Leverage predefined signals in graphs

Create parameterized signals for simulation and optimization

### Improve calculation performance in graphs

Tips and tricks to speed up your calculations in Boulder Opal

### Understand batches and broadcasting in Boulder Opal

Approaches to handle multidimensional data efficiently in graphs

### How to calculate and optimize with graphs

Create graphs for computations with Boulder Opal

### How to represent quantum systems using graphs

Represent quantum systems for optimization, simulation, and other tasks using graphs

### How to perform optimization and simulation in the same calculation

Perform calculations using optimization results in a single graph

### How to reuse graph definitions in different calculations

Reapply graph nodes for multiple applications

### How to create analytical signals for simulation and optimization

Use predefined signals from Boulder Opal

### How to define continuous analytical Hamiltonians

Use analytical expressions to construct your Hamiltonian