A method of controlling a melt pressure of an injection molding apparatus, the method comprising: receiving a melt pressure profile , the melt pressure profile comprising a plurality of setpoints (P0, P1, P2, P3, P4, P5) that each define a desired melt pressure for the injection molding apparatus, the melt pressure profile extending between the setpoints (P0, P1, P2, P3, P4, P5), and each setpoint being separated from the other setpoints (P0, P1, P2, P3, P4, P5) by a time period (T1, T2, T3, T4, T5) that defines at least a portion of an injection molding process during which a thermoplastic is being injected into a mold cavity; determining the melt pressure profile at one or more intervals located between the setpoints (P0, P1, P2, P3, P4, P5), wherein each of the one or more intervals and the setpoints (P0, P1, P2, P3, P4, P5) are separated by time and wherein each of the one or more intervals define a desired melt pressure for the injection molding apparatus; and at each of the one or more intervals, controlling the injection molding apparatus based upon the desired melt pressure defined by the melt pressure profile at each of the one or more intervals; wherein, for at least two immediately adjacent setpoints (P0, P1, P2, P3, P4, P5), the desired melt pressure at each of the one or more intervals located between the setpoints (P0, P1, P2, P3, P4, P5) is different from the desired melt pressure at each of the at least two immediately adjacent setpoints (P0, P1, P2, P3, P4, P5); wherein the melt pressure profile is determined using a curve-fitting algorithm; the method characterized in that for at least two immediately adjacent setpoints (P0, P1, P2, P3, P4, P5), a plurality of intervals are located between the setpoints and the desired melt pressure at each interval between the setpoints (P0, P1, P2, P3, P4, P5) is different from the desired melt pressure at each immediately adjacent interval that lies between the setpoints (P0, P1, P2, P3, P4, P5). receiving a melt pressure profile , the melt pressure profile comprising a plurality of setpoints (P0, P1, P2, P3, P4, P5) that each define a desired melt pressure for the injection molding apparatus, the melt pressure profile extending between the setpoints (P0, P1, P2, P3, P4, P5), and each setpoint being separated from the other setpoints (P0, P1, P2, P3, P4, P5) by a time period (T1, T2, T3, T4, T5) that defines at least a portion of an injection molding process during which a thermoplastic is being injected into a mold cavity; determining the melt pressure profile at one or more intervals located between the setpoints (P0, P1, P2, P3, P4, P5), wherein each of the one or more intervals and the setpoints (P0, P1, P2, P3, P4, P5) are separated by time and wherein each of the one or more intervals define a desired melt pressure for the injection molding apparatus; and at each of the one or more intervals, controlling the injection molding apparatus based upon the desired melt pressure defined by the melt pressure profile at each of the one or more intervals; wherein, for at least two immediately adjacent setpoints (P0, P1, P2, P3, P4, P5), the desired melt pressure at each of the one or more intervals located between the setpoints (P0, P1, P2, P3, P4, P5) is different from the desired melt pressure at each of the at least two immediately adjacent setpoints (P0, P1, P2, P3, P4, P5); wherein the melt pressure profile is determined using a curve-fitting algorithm; the method characterized in that for at least two immediately adjacent setpoints (P0, P1, P2, P3, P4, P5), a plurality of intervals are located between the setpoints and the desired melt pressure at each interval between the setpoints (P0, P1, P2, P3, P4, P5) is different from the desired melt pressure at each immediately adjacent interval that lies between the setpoints (P0, P1, P2, P3, P4, P5). <EOS>