*Curve()

Creates a curve entity to capture non-linear characteristics or to describe constraint paths for high-pair joint types.

Syntax

*Curve(crv_name,"crv_label",2D|3D CARTESIAN|PARAMETRIC, [WRITE|NOWRITE], [CONTROL_POINTS|CURVE_POINTS], [OPEN|CLOSED])

Arguments

crv_name
The variable name of the curve.
Data type: varname
crv_label
The descriptive label of the curve.
Data type: label
2D|3D
Determines if the curve is two dimensional or three dimensional.
CARTESIAN| PARAMETRIC
Determines if the curve is described by xy (xyz) or uxy (uxyz) data.
WRITE| NOWRITE
Determines whether or not the curve data is exported to the solver input deck.
CONTROL_POINTS|CURVE_POINTS
Determines if the points are to be exactly on the curve ( CURVE_POINTS ) or used to fit the curve ( CONTROL_POINTS ).
OPEN|CLOSED
Determines whether or not the first and last point should be connected for a closed curve. CLOSED results in a continuous path for a constraint using this curve.

Example

*Point( p_0, "Point 0", )
*Body( b_0, "Body 0", , , )
*Curve( crv_0, "Curve 0", WRITE )
*Motion( mot_0, "Motion 0", JOINT, MODEL.j_0, TRANS )
*TransJoint( j_0, "Joint 0", MODEL.B_Ground, MODEL.b_0
 , MODEL.P_Global_Origin, MODEL.p_0 )

Context

*BeginMdl()

*DefineAnalysis()

*DefineSystem()

Properties

Table 1.
Property Returns Data Type Description
dim integer The dimension of the curve (0 - 2D, 1 - 3D).
eq_type integer The type of curve (0 - cartesian, 1 - parametric).
label string The descriptive label of the curve.
lin_extrap integer Determines if the keyword for linear extrapolation is exported to the solver input deck.
min_par real Defines the minimum value of the curve parameter for a user-defined curve.
max_par real Defines the maximum value of the curve parameter for a user-defined curve.
open_closed integer Open-closed setting for the curve ^(0 - open, 1 - closed).
state boolean Control state (TRUE or FALSE).
user boolean 0 - properties are not user-defined.^1 - user-defined properties.
order integer Specifies the order of the interpolation of the curve.
varname string The variable name of the curve.
write integer Setting for the ^WRITE|NOWRITE^ keyword ^(0 - write, 1 - nowrite).
u CurveVector The vector of data for "u" which is exported to the solver input deck.
u_comp string The "component" setting when the "u" data comes from FILE.
u_datatype string The "type" setting when the "u" data comes from FILE.
u_end integer Index of the final entry in the "u" data vector.
u_file string String for the filename that is the source of the "u" values.
u_incr boolean The increment between the "u" values.
u_last boolean The value of the last "u" entry.
u_math NumericVector Vector of floats when the "u" type is MATH. One float per "u" value.
u_offset real Offset for the "u" data.
u_request string The "request" setting when the "u" data comes from FILE.
u_scale real Scale factor for the "u" data.
u_start integer Index for the first entry in the "u" data vector.
u_type integer 0 - FILE, 1 - VALUE, 2 - MATH.
u_value NumericVector Vector of floats when the "u" type is VALUE. One float per "u" value.
x CurveVector The vector of data for "x" which is exported to the solver input deck.
x_comp string The "component" setting when the "x" data comes from FILE.
x_datatype string The "type" setting when the "x" data comes from FILE.
x_end integer Index of the final entry in the "x" data vector.
x_file string String for the filename that is the source of the "x" values.
x_incr boolean The increment between the "x" values.
x_last boolean The value of the last "x" entry.
x_math NumericVector Vector of floats when "x" type is MATH. One float per "x" value.
x_offset real Offset for the "x" data.
x_request string The "request" setting when the "x" data comes from FILE.
x_scale real Scale factor for the "x" data.
x_start integer Index for the first entry in the "x" data vector.
x_type integer 0 - FILE, 1 - VALUE, 2 - MATH.
x_value NumericVector Vector of floats when the "x" type is VALUE. One float per x value.
y CurveVector The vector of data for "y" which is exported to the solver input deck.
y_comp string The "component" setting when the "y" data comes from FILE.
y_datatype string The "type" setting when the "y" data comes from FILE
y_end integer Index of the final entry in the "y" data vector.
y_file string String for the filename that is the source of the "y" values.
y_incr boolean The increment between the "y" values.
y_last boolean The value of the last "y" entry.
y_math NumericVector Vector of floats when the "y" type is MATH.^One float per "y" value.
y_offset real Offset for the "y" data.
y_request string The "request" setting when the "y" data comes from FILE.
y_scale real Scale factor for the "y" data.
y_start integer Index for the first entry in the "y" data vector.
y_type integer 0 - FILE, 1 - VALUE, 2 - MATH.
y_value NumericVector Vector of floats when the "y" type is VALUE.^One float per "y" value.
z CurveVector The vector of data for "z" which is exported to the solver input deck.
z_comp string The "component" setting when the "z" data comes from FILE.
z_datatype string The "type" setting when the "z" data comes from FILE.
z_end integer Index of the final entry in the "z" data vector.
z_file string String for the filename that is the source of the "z" values.
z_incr boolean The increment between the "z" values.
z_last boolean The value of the last "z" entry.
z_math NumericVector Vector of floats when the "z" type is MATH. One float per "z" value.
z_offset real Offset for the "z" data.
z_request string The "request" setting when the "z" data comes from FILE.
z_scale real Scale factor for the "z" data.
z_start integer Index for the first entry in the "z" data vector.
z_type integer 0 - FILE, 1 - VALUE, 2 - MATH.
z_value NumericVector Vector of floats when the "z" type is VALUE. One float per "z" value.

Comments

Curves may used to specify properties of entities, such as bushing stiffness. Some curves can be used to specify several properties. Curves that are referenced in expressions should reference varname.x and varname.y. For example, crv_o.x.

Curves may also be used to specify a constraint path for high-pair joints. Examples of these include *PointToCurveJoint(), *PointToSurfaceJoint(), *CurveToCurveJoint(), *CurveToSurfaceJoint() and *SurfacetoSurfaceJoint().