درون‌یابی مقید با استفاده از اسپلاین مکعبی ارمیت

نویسندگان
دانشگاه خوارزمی تهران، دانشکده علوم ریاضی و کامپیوتر
چکیده
در این مقاله نوع خاصی از مسئلۀ درون‌یابی حافظ شکل را بررسی می‌کنیم که در آن داده‌ها به‌کمک دو خم درجۀ دو، به‌عنوان کران بالا و پایین، محدود شده‌اند. هدف ارائۀ یک درون‌یاب است که در ضمن هموار بودن در محدودۀ کران بالا و پایین تحمیل شده به‌وسیلۀ مسئله بیافتد، به‌عبارت دقیق‌تر، نمودار هندسی درون‌یاب به‌طور کامل بین دو سهمی از پیش معلوم قرار بگیرد. برای حل این مسئله از اسپلاین مکعبی ارمیت استفاده می‌کنیم، این خانواده از اسپلاین‌ها شرط همواری درجۀ اول را دارند و مجهز به پارامترهای کمکی هستند که می‌توان از آن‌ها برای اعمال محدودیت‌های دیگر کمک گرفت. با اعمال محدودیت‌ها و حل یک مسئلۀ برنامه‌ریزی خطی به نمودار جواب می‌رسیم. برای رسیدن به جواب‌های می‌توانیم از تکنیک مینیمم‌سازی انرژی استفاده ‌کنیم
کلیدواژه‌ها

عنوان مقاله English

Constrained Interpolation via Cubic Hermite Splines

چکیده English

Introduction

In industrial designing and manufacturing, it is often required to generate a smooth function approximating a given set of data which preserves certain shape properties of the data such as positivity, monotonicity, or convexity, that is, a smooth shape preserving approximation.

It is assumed here that the data is sufficiently accurate to warrant interpolation, rather than least squares or other approximation methods. The shape preserving interpolation problem seeks a smooth curve/surface passing through a given set of data, in which we priorly know that there is a shape feature in it and one wishes the interpolant to inherit these features. One of the hidden features in a data set may be its boundedness. Therefore, we have a data set, which is bounded, and we already know that. This happens, for example, when the data comes from a sampling of a bounded function or they reflect the probability or efficiency of a process.

Scientists have proposed various shape-preserving interpolation methods and every approach has its own advantages and drawbacks. However, anyone confesses that splines play a crucial role in any shape-preserving technique and every approach to shape-preserving interpolation, more or less, uses splines as a cornerstone.

This study concerns an interpolation problem, which must preserve boundedness and needs a smooth representation of the data so the cubic Hermite splines are employed.

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کلیدواژه‌ها English

Shape-preserving
Constrained Interpolation
Cubic Hermite Splines
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