This article may be too technical for most readers to understand.(August 2016) |
Developer(s) | Ventana Systems, Inc. |
---|---|
Initial release | 1990 |
Stable release | Version 9.3.2 / July 2022 |
Written in | C |
Operating system | Windows and OS X applications, Linux and iOS libraries |
Type | Simulation software |
License | Proprietary |
Website | vensim |
Vensim is a simulation software developed by Ventana Systems. It primarily supports continuous simulation (system dynamics), with some discrete event and agent-based modelling capabilities. It is available commercially and as a free "Personal Learning Edition".
Vensim provides a graphical modeling interface with stock and flow and causal loop diagrams, on top of a text-based system of equations in a declarative programming language. It includes a patented method for interactive tracing of behavior through causal links in model structure (the patent expired in 2012), [1] [2] [3] as well as a language extension for automating quality control experiments on models called Reality Check. [4]
The modeling language supports arrays (subscripts) and permits mapping among dimensions and aggregation. Built-in allocation functions satisfy constraints that are sometimes not met by conventional approaches like logit. [5] It supports discrete delays, queues and a variety of stochastic processes.
There are multiple paths for cross sectional and time-series data import and export, including text files, spreadsheets and ODBC. Models may be calibrated against data using optimization, Kalman Filtering [6] or Markov chain Monte Carlo methods. Sensitivity analysis options provide a variety of ways to test and sample models, including Monte Carlo simulation with Latin Hypercube sampling.
Vensim model files can be packaged and published in a customizable read-only format that can be executed by a freely available Model Reader. This allows sharing of interactive models with users who do not own the program and/or who the model author does not wish to have access to the model's code base. [7]
Vensim is general-purpose software, used in a wide variety of problem domains. Common or high-profile applications include:
Rendering or image synthesis is the process of generating a photorealistic or non-photorealistic image from a 2D or 3D model by means of a computer program. The resulting image is referred to as a rendering. Multiple models can be defined in a scene file containing objects in a strictly defined language or data structure. The scene file contains geometry, viewpoint, textures, lighting, and shading information describing the virtual scene. The data contained in the scene file is then passed to a rendering program to be processed and output to a digital image or raster graphics image file. The term "rendering" is analogous to the concept of an artist's impression of a scene. The term "rendering" is also used to describe the process of calculating effects in a video editing program to produce the final video output.
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