Guidelines For Constructing Vector Components
change_over_time_in_X
[X]
change in a quantity X over a time-interval, which should be defined by the bounds of the time coordinate.
[horizontal_]convergence_of_X
[X] m-1
[horizontal] convergence of a vector X (i.e. the divergence multiplied by -1); if X does not have a vertical component then "horizontal" should be omitted.
correlation_of_X_and_Y[_over_Z]
1
correlation coefficient for variations (over Z e.g. time, longitude) of X and Y. X and Y are ordered alphabetically.
covariance_of_X_and_Y[_over_Z]
[X]*[Y]
covariance for variations (over Z e.g. time, longitude) of X and Y. X and Y are ordered alphabetically.
component_derivative_of_X
[X] m-1
derivative of X with respect to distance in the component direction, which may be northward, southward, eastward, westward, x or y. The last two indicate derivatives along the axes of the grid, in the case where they are not true longitude and latitude.
derivative_of_X_wrt_Y
[X]/[Y]
dX/dY.
direction_of_X
degree
direction of a vector, a bearing.
[horizontal_]divergence_of_X
[X] m-1
[horizontal] divergence of a vector X; if X does not have a vertical component then "horizontal" should be omitted.
histogram_of_X[_over_Z]
1
histogram (i.e. number of counts for each range of X) of variations (over Z) of X. The data variable should have an axis for X.
integral_of_Y_wrt_X
[X]*[Y]
int Y dX. The data variable should have an axis for X specifying the limits of the integral as bounds.
ln_X
1
natural logarithm of X. X must be dimensionless.
log10_X
1
common logarithm (i.e. base 10) of X. X must be dimensionless.
magnitude_of_X
[X]
magnitude of a vector X.
probability_distribution_of_X[_over_Z]
1
probability distribution (i.e. a number in the range 0.0-1.0 for each range of X) of variations (over Z) of X. The data variable should have an axis for X.
probability_density_function_of_X[_over_Z]
1/[X]
PDF for variations (over Z) of X. The data variable should have an axis for X.
product_of_X_and_Y
[X]*[Y]
X*Y. If X and Y are both scalars or both components of vectors, they are put in alphabetical order. If one of them is the component of a vector, it is put first i.e. the vector component is X, the scalar is Y.
ratio_of_X_to_Y
[X]/[Y]
X/Y.
square_of_X
[X]*[X]
X*X.
tendency_of_X
[X] s-1
derivative of X with respect to time.
source:http://cf-pcmdi.llnl.gov/documents/cf-standard-names/guidelines
Monday, July 2, 2007
~*Vector Component*~
Vector Components
A vector is a quantity which has magnitude and direction. Displacement, velocity, acceleration, and force are the vector quantities which we have discussed thus far in our course. In the first couple of units of our course, all vectors which we discussed were simply directed up, down, left or right. When there was a free-body diagram depicting the forces acting upon an object, those forces were directed in one dimension - up, down, left or right. When an object had an acceleration and we described its direction, it was directed in one dimension - up, down, left or right. Now in this unit, we begin to see examples of vectors which are directed in two dimensions - upward and rightward, northward and westward, eastward and southward, etc.
In situations in which vectors are directed at angles to the customary coordinate axes, a useful mathematical trick will be employed to transform the vector into two parts, with each part being directed along the coordinate axes. For example, a vector which is directed northwest can be thought of as having two parts - a northward and a westward part. A vector which is directed upward and rightward can be thought of as having two parts - an upward and a rightward part.
Any vector directed in two dimensions can be thought of as having an influence in two different directions. That is, it can be thought of as having two parts. Each part of a two-dimensional vector is known as a component. The components of a vector depict the influence of that vector in a given direction. The combined influence of the two components is equivalent to the influence of the single two-dimensional vector. The single two-dimensional vector could be replaced by the two components.
source:http://www.glenbrook.k12.il.us/GBSSCI/PHYS/CLASS/vectors/u3l1d.html
A vector is a quantity which has magnitude and direction. Displacement, velocity, acceleration, and force are the vector quantities which we have discussed thus far in our course. In the first couple of units of our course, all vectors which we discussed were simply directed up, down, left or right. When there was a free-body diagram depicting the forces acting upon an object, those forces were directed in one dimension - up, down, left or right. When an object had an acceleration and we described its direction, it was directed in one dimension - up, down, left or right. Now in this unit, we begin to see examples of vectors which are directed in two dimensions - upward and rightward, northward and westward, eastward and southward, etc.
In situations in which vectors are directed at angles to the customary coordinate axes, a useful mathematical trick will be employed to transform the vector into two parts, with each part being directed along the coordinate axes. For example, a vector which is directed northwest can be thought of as having two parts - a northward and a westward part. A vector which is directed upward and rightward can be thought of as having two parts - an upward and a rightward part.
Any vector directed in two dimensions can be thought of as having an influence in two different directions. That is, it can be thought of as having two parts. Each part of a two-dimensional vector is known as a component. The components of a vector depict the influence of that vector in a given direction. The combined influence of the two components is equivalent to the influence of the single two-dimensional vector. The single two-dimensional vector could be replaced by the two components.
source:http://www.glenbrook.k12.il.us/GBSSCI/PHYS/CLASS/vectors/u3l1d.html
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