data_element create spline
Allows for creation of the spline object.
Format:
data_element create spline |
|---|
spline_name = | a new spline |
adams_id = | adams_id |
comments = | string |
x_result_set_component_name = | an existing component |
x = | real |
y_result_set_component_name = | an existing component |
y = | real |
z_result_set_component_name = | an existing component |
z = | real |
linear_extrapolate = | boolean |
x_units = | string |
y_units = | string |
z_units = | string |
file_name = | string |
Example:
data_element create spline & |
|---|
spline_name = | spline__1 & |
adams_id = | 2 & |
comments = | "a new spline" & |
linear_extrapolate = | yes & |
x_units = | mm & |
y_units = | mm & |
z_units = | degree & |
file_name = | "c:\spline.txt" |
Description:
Parameter | Value Type | Description |
|---|
spline_name | A New Spline | Specifies the name of the new spline. You may use this name later to refer to this spline. |
adams_id | Adams_id | Specifies an integer used to identify this element in the Adams data file. |
comments | String | Specifies comments for the object being created or modified. |
x_result_set_component_name | An Existing Component | Specifies the result set component containing values for the spline X (independent) variable. |
x | Real |
y_result_set_component_name | An Existing Component | Specifies the result set component containing values for the spline Y (dependent) variable. |
y | Real |
z_result_set_component_name | An Existing Component | Specifies the result set component containing values for the spline Z (independent) variable. |
z | Real |
linear_extrapolate | Boolean |
units | String | Allows you to specify the type of units to be used for this object. |
x_units | String | Allows you to specify the type of X units to be used for this object. |
y_units | String | Allows you to specify the type of Y units to be used for this object. |
z_units | String | Allows you to specify the type of Z units to be used for this object. |
file_name | String |
Extended Definition:
1. A spline interpolates between discrete data for a user-provided function or a utility subroutine called by a user-written subroutine.
You use the spline to provide one or two independent variables and one dependent variable for each data point you want to enter. Adams uses curve fitting techniques to interpolate between data points to create a continuous function. If the spline data has one independent variable, Adams uses a cubic polynomial to interpolate between points.
If the spline data has two independent variables, Adams first uses a cubic interpolation method to interpolate between points of the first independent variable and then uses a linear method to interpolate between curves of the second independent variable.
2. To use the discrete data input with a spline, you must write either a function expression that includes one of the two Adams spline functions (AKISPL function and CUBSPL function) or a user-written subroutine that calls one of the two spline utility subroutines (AKISPL subroutine and CUBSPL subroutine).
3. These spline functions and utility subroutines use two different interpolation methods. The AKISPL function and the AKISPL subroutine use the Akima method of interpolation. The Akima method is a local cubic curve fitting technique. The CUBSPL function and the CUBSPL subroutine use the traditional cubic method of interpolation. The traditional cubic method is a global cubic curve fitting technique.
Both the Akima method and the traditional cubic method use cubic polynomials to interpolate values that fall between two adjacent points on a curve. Both provide closer approximations than other curve fitting techniques (for example, Lagrange polynomials, difference tables, and Fourier series). For data with two independent variables, Adams uses a linear interpolation technique to interpolate values that fall between curves.
4. If you have created a spline in Adams View, you may wish to plot the data points or the interpolated curve to verify that you entered the data correctly and that the spline interpolates smoothly. To do this, first use the 'NUMERIC_RESULTS CREATE SPLINE' command to create a result set from the spline. This result set will contain components composed of the spline data points. You can then plot the result set (that is, the spline data points) with the XY_PLOTS command. You may also use the 'NUMERIC_RESULTS CREATE INTERPOLATION' command to interpolate more points from the data-point result set, and then plot those.The Adams View CUBIC and AKIMA interpolation options use the same methods as the Adams CUBSPL and AKISPL functions, respectively.
5. Normally, entity names are composed of alphabetic, numeric, or '_' (underscore) characters, and start with an alphabetic or '_' character. They may be any length. For more information, see
Using Extended Names.
By enclosing the name in double quotes, you may use other printable characters, or start the name with a numeral. If a name contains characters, or starts with a numeral, you must always quote the name when entering it.
Note that you can specify the parentage of an entity (for example, what part "owns" a marker or a geometry element) when you CREATE it by changing the name. If you enter just the entity name, then the default parent will be assigned by Adams View. If you type in the full name, then you may over ride the default parent. In most cases, when creating an entity, Adams View will provide a default name. The default name that Adams View provides will specify the parentage that it has assumed.
You may, or course, delete this name and use your own. The form of a full name is:
"...._NAME.GRAND_PARENT_NAME.PARENT_NAME.ENTITY_NAME"
The number of levels used varies from case to case and the parentage must exist before an entity can be assigned to it.
6. When you use the FILE ADAMS_DATA_SET WRITE command, Adams View writes an Adams data file for your model. Adams requires that each modeling element be identified by a unique integer identifier. If you use this parameter to specify a non-zero identifier, Adams View will use it in the corresponding statement in the Adams data file.
You may also enter zero as an identifier, either explicitly or by default. The next time you write an Adams file, Adams View will replace the zero with a unique, internally-generated identifier.
Adams View will permanently store this identifier with the element just as if you had entered it yourself.
Normally, you would let all identifiers default to zero, and Adams View would generate the identifiers for you. You are never required to enter a non-zero identifier. You only need to specify it if, for some reason, you wish to control the Adams file output.
7. When an Adams Solver data file (.adm) is read into Adams View, all comments associated with a statement (from the end of the previous statement through the end of the current statement) are stored with the object. Comments in the data file can be associated with model.
These comments must follow the title statement and be followed by the comment 'END OF MODEL COMMENTS'. This string must be uppercase.
When an Adams Solver data file is written, the comments for an object are written before the statement corresponding to the object.
8. You must supply a Y value corresponding to each combination of X and Z values. First list the component with values for each X value at the first Z value, then the component with values for each X value at the second Z value, and so on.
9. Since this object can be used in a variety ov contexts, AdamsAdams View can not determine what type of units it should have. By telling Adams View what the unit type for this object is Adams View can preform the proper conversions on the values you specify.
10. In the Adams View database and command language, units specification for splines can be done in either of two ways: via parameters "x_units", "y_units" and "z_units"; or by a single "units" parameter. If the Spline has this "units" parameter defined, it will be mapped to the Y Units field in this dialog.
Cautions:
1. Adams View will not allow you to have two splines with the same full name, so you must provide a unique name.