# Terminology word list

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### LP
Linear programming (LP), a mathematical method for finding the best possible outcome, from a linear model.

### MIP 
Mixed integer problem (MIP), optimization technique for solving problems with both continuous (real-valued) and discrete (integer or binary) decision variables.

### SDP
Stochastic dynamic programming (SDP), a mathematical optimization technique for sequential decision-making problems where outcomes are affected by random uncertainty over time, aiming to maximize expected future return.

### SDDP
Stochastic dual dynamic programming (SDDP), similar in concept to SDP, but uses sampling to avoid curse of dimensionality.

### curse of dimensionality
When an increase in problem size exponentially increases solution time (or solution space).

### MPI
Message parsing interface (MPI) - framework to communicate across computer processes, used to parallelize work over distributed memory. Can be used across CPUs, computer nodes or computers. Gold standard for distributed memory parallelization.

### deterministic
Having a clear cause-effect relatioship.

### stochastic
Opposed to deterministic, there is an uncertainty present. Etymology: greek, "guess".

### YAML
File format, file ending .yaml or .yml. .yml pronounced as "yaml".

### Markov model
A model describing a system which is changing over time but the next state is only dependent on the current state, not previous states.

### future cost function
A function or variable containing the estimate of the cost of operating as planned from a given time and up to a defined future, ex. from today up until end of simulation horizon.

### K-cost
Cost estimate from backward phase of iteration. Upper bound of optimal cost.

### F-cost
Cost estimate from forward phase of iteration. Lower bound of optimal cost.

### water value
The opportunity cost of not using water at a given time and state of reservoirs. Dual value of reservoir volume.

### price taker
A market actor which does not influence the price. Large actors whose actions can influence or control the market price can be price makers.

### convex
For functions, the property that the function is continous and any line between two points on the graph of the function lie on or above the graph; "smiling". Important property because it guarantees a solution, i.e., the existence of a global minimum which can be found by moving along the function in any direction.

### concave
Opposite to convex.