I know the difference between a constant value and a variable value. A constant takes a fixed value and doesn't change. A variable value may take multiple values. But I don't understand the difference between a variable and a parameter. I'm thinking that they are somehow related though...
2007-09-26 08:51:46 · 5 answers · asked by the redcuber 6 in Science & Mathematics ➔ Mathematics
Loosely speaking, the term parameter is used for an argument which is intermediate in status between a variable and a constant.
That's a quote from wikipedia which see.
2007-09-26 09:12:42 · answer #1 · answered by ? 5 · 0⤊ 0⤋
Personally, I think it depends on the context. If you are talking about a statistical model, say a linear regression, I would say that model 'variables' or model parameters' are the same. If you are looking at a simulation of some sort I think they can be different. For example, I do a lot of modeling and simulation of decision trees. The simulation will use many variables such as outcome (or path) probabilities and cost variables. To do uncertainty analysis I can actually define each variable (whether it is a path probability, cost, or whatever) by a probability distribution. Now, these distributions are based on unique parameters (e.g. a normal distribution is based on the mean and standard deviation). In this case I would consider model variables and model parameters to be different. But in my work I find it very common for people to use 'variable' and 'parameter' interchangeably no matter what the context.
2016-05-19 02:02:59 · answer #2 · answered by ? 3 · 0⤊ 0⤋
They kinda are related. But a 'parameter' is assumed to be constant while the function is being evaluated.
However......... In parametric analysis one usually looks for values of a 'parameter' which make the function behave 'nicely' or get 'weird' (in some way). In that case it -is- almost like a variable. The only good example I can think of offhand is in quadratics where the discriminant (b² - 4ac) determins if the roots are complex or not.
Doug
2007-09-26 09:00:48 · answer #3 · answered by doug_donaghue 7 · 1⤊ 0⤋
A parameter is a constant that can vary.
For example, the point-slope form of a line is y = mx+b. m and b are the slopes and y-intercepts respectively. These are constant for each individual line. But you're allowed to choose any m and b you want to get different lines.
Similarly, the equation of a circle centered at the origin is x^2+y^2 = r^2. x and y are variables. r is a parameter for the circle that is fixed for a given circle but you can vary to get different circles in this family of circles.
2007-09-26 09:06:12 · answer #4 · answered by np_rt 4 · 0⤊ 0⤋
A parameter is just a variable that is passed to a function. For example, if you have the function f(x), x is a variable and a parameter.
2007-09-26 08:55:00 · answer #5 · answered by MC 2 · 0⤊ 0⤋